Table of contents
3. INTERPRETING THE REQUIREMENTS IN ISO 9001 FOR SOFTWARE DEVELOPMENT AND MAINTENANCE
Now, let us take a detailed look at the requirements in ISO 9001, seen from the viewpoint of a company developing software.
Remember that the standard was originally intended for the manufacturing industry, and its application to software development is a special case. In this section, the requirements are interpreted for software development approximately in accordance with ISO 9000-3 and the TickIT guide.
The requirements in the standard are structured into 20 main quality elements. These elements are seen as the major parts of a quality system, and each element is a well-known concept in the quality management community. In this chapter, we will go through the quality elements in turn and describe what they imply for the development and maintenance of software. In the heading for each quality element we include the corresponding paragraph number in ISO 9001 in brackets.
Especially with software, when an auditor encounters a deficiency, there may be more than one paragraph in the standard to raise the non-conformance against. For example, improper documentation of testing may be raised against either 4.5 "Document control", 4.4.8 "Design validation", or 4.10 "Inspection and testing".
Quality elements of ISO 9001
Management responsibility (4.1)
This element covers the general responsibilities of a company's management. The requirements consist of three parts: Quality policy, Organization and Management review.
The concept of quality policy is central for ISO 9001. The quality policy is viewed as the root, from which the rest of the quality system grows.
The standard does not explicitly require a supplier to produce quality products. Instead, the standard requires the supplier management to issue a quality policy, where it says that the company shall produce quality products.
Notice that not all suppliers have product quality as important aims. Quality is important mainly when one wants the customers to return. For example, there are organizations whose only goal is to sell products or services regardless of the needs of the customer or even the quality of the product. Such organizations can not meet ISO 9001.
The quality policy shall:
- define the management's commitment to quality
- define the company's objectives regarding quality, i.e. what does the management mean with "quality"
- be relevant to the customer's needs
- be understood in the organization
- be implemented.
Usual reasons to raise non-conformances regarding quality policy are either that the statement is to vague or that the policy is not understood by some staff. Employees in the company do not have to know the quality policy by heart, but they are expected to know the gist of it.
More serious non-conformances have to do with the implementation of the policy. This requirement in the standard forms a kind of "general clause" which can be used to raise non-conformances on slackness in different parts of the company's operation. For example, I once audited a company where I could see that the number of unresolved customer complaints had been increasing for some time, because the management had not assigned enough resources to the resolution of customer complaints.
However, the company's quality policy said clearly that meeting the customers' needs was central for the company. Thus, the company did not conform to its own quality policy, and a non-conformance was duly raised. Such a non-conformance should not be taken lightly!
Quality policies may be formulated in many different ways. The following is one example:
"XYZ Software Inc. bases its commercial success on the production of quality products and services for its customers. By quality we mean timely delivery of reliable software, prompt response and action on customer complaints, and fulfillment of other customer needs.
We achieve quality through motivated and skilled staff, defined work procedures, and intensive review and testing activities.
Each employee is responsible for the quality of his or her work result."
I once audited part of a very large European company, and it was interesting to see, that although this company is formalistic in many ways in most of its operations, software development was not. The software engineers were apparently experienced and competent, and they worked together in an informal way. No real project managers were appointed, but the more senior software engineers fixed it among themselves. Who should do the testing was agreed on the spur when the need occurred. The project was largely left on its own by the line management. I saw no indications that the software produced was of inferior quality, but the handling of software development was still not up to ISO 9001.
The most important and difficult part of the paragraph on organization has to do with responsibility and authority. Traditionally, in the software community we have tended to use informal organizations with vague assignments of responsibility and, especially, authority. This is not acceptable if we claim fulfillment of ISO 9001.
The standard requires documentation of responsibility, authority and interrelation of all personnel affecting quality. Since virtually all staff in a software organization can influence product quality, this means that if a person has a responsibility or an authority, it must be formally assigned.
If a person has a responsibility, it shall be formally assigned by the appropriate manager. The person shall also have enough authority to fulfil his/her responsibility. The authority shall be formally issued.
Sometimes the concept of "responsibility" creates some confusion. In the context of ISO 9001, responsibility means a duty to act on ones own accord when something has to be done, without being told. To do what somebody else tells you to do is not a responsibility. Usually, the view is that managers and other key positions have responsibilities, while individual software engineers do as they are told and as company and project rules prescribe.
What I would have liked to see in the German company was formal assignment of responsibility and authority to line managers, project managers, testers, review leaders, software librarians and others.
The existence of a responsibility which can not be fulfilled is a non-conformance to ISO 9001. For example, I have found project managers with the clearly stated responsibility to meet a time schedule. However, when asked, they have admitted that they don't have the authority to direct the work of project members.
As mentioned, also interrelations shall be defined and documented. This is a popular area for auditors to dig into. Especially, the interrelations between project managers and line managers are interesting. Who decides what, how is reporting done, how is approval and control defined? Areas where an auditor would expect to find interfaces defined include:
- project - line
- project - customer
- project - maintenance organization
- software development - hardware development
- maintenance organization - helpdesk
- sales - development
The standard covers two more areas under the heading "Organization", namely Resources and Management Representative.
The first area requires the supplier to identify the requirements for resources, to provide adequate resources, and to assign trained personnel.
The second area requires the appointment of a management representative with authority and responsibility to
- ensure that the company fulfills the requirements in ISO 9001
- report the performance of the quality system to company management.
Usually, the quality manager is this management representative.
This paragraph says that the supplier's management shall periodically review the suitability and effectiveness of the quality system. This is often done by once a year having the quality manager presenting the results of quality audits, statistics of customer complaints, records of corrective actions, and other relevant material at a minuted management meeting. The documentation of this meeting should note who attended, what was presented, what decisions were taken etc.
Quality system (4.2)
According to ISO, a quality system comprises "the organizational structure, responsibilities, procedures, processes and resources for implementing quality management".
Paragraph 4.2 requires that the supplier's quality system be documented and implemented. Procedures, rules, decisions etc needed to fulfill ISO 9001 shall be in writing. Existing procedures, rules etc shall be adhered to.
Notice that this last requirement may be a trap for over-zealous organizations. If you have a rule, procedure etc, which is not required by ISO 9001, the standard still requires that it be adhered to.
The paragraph further requires that the outline structure of the documentation covering the quality system be defined in a quality manual, which shall contain or reference the documentation of the quality system.
This paragraph in the standard also includes requirements for quality plans. We cover quality plans in para 220.127.116.11.
A typical use of this paragraph of the standard can be seen in the following example. I was a member of a group auditing a large organization. We found a number of minor non-conformances, which the auditee organization corrected at once. For example, we found people using non-approved design documents, lack of written procedures for minor activities etc. At the conclusion of the audit, there were no non-conformances open; they had all been closed during the audit. However, we still raised a non-conformance against paragraph 4.2 in the standard. An audit is a sampling, and we had just made spot-checks. Since we had found so many minor non-conformances through spot-checking, we were convinced that there were further short-comings to be found. So we raised a non-conformance on general weakness of the quality system, and required the auditee to make a thorough review of it.
Other typical non-conformances against 4.2 in ISO 9001 are the existence of written procedures, which are not adhered to, as well as suitable development processes, which are not documented.
Contract review (4.3)
Many years ago, I was appointed project manager of a quite large project. I was given limits in calendar time and staffing, and I planned and calculated how the project should achieve the software which our sales department had promised the customer. All limits were absolute, since the price and delivery date had already been agreed with the customer. When my planning was finished, I put on a tie and went to present my plan to the company management in our Board Room. I showed a few viewgraphs with time-schedules, activities and manning. The presentation went quite smooth, and I even received one or two approving grunts from the managing director. Then I put on my last slide, and I still vividly remember the sudden drop in temperature in the room. The slide said: "This is why it is not possible" and listed a few reasons. There were no reserves. There were large holes in the staffing. The calendar time was too short for the manning up of the project. The requirements were incomplete and unstable. We would be using new concepts, of which we had no experience. I had planned too little time for reviews.
The atmosphere in the room became cold and uncomfortable. The expected barrage started: "Are you really sure that it's impossible?" "I think you have been overly conservative in your estimates." "This is a critical project for our company. We may loose the customer if we don't deliver on time." Inexperienced though I was, I did not buckle, but held on to my conclusion that the task was impossible. The project was started anyhow, with another project manager, and after two years and about 20 million dollars, it was cancelled. Of course, it may feel good to say "I told you so!", but I still feel that the debacle was unnecessary.
In my experience, many of the problems with software projects stem from overselling. The sales department has agreed with the customer about a time-schedule and/or a price which the development department can not achieve. The developers' failure to meet the contract is then assumed to reflect on their ability to handle software projects, while in fact the task was impossible from the beginning.
More recently I observed another example of the same phenomenon. I was auditing a large organization developing software. I happened on the minutes from a decision meeting for a development project. In the minutes, the project manager was reported saying "We can only meet the delivery date if everything goes right with the project." The minutes then showed that the meeting (of managers) had decided to go forward without changing the delivery date. I checked up on the project, and it was already late. It was clear that it could not meet the delivery date. I said to one of the participants of the decision meeting: "All of you in that meeting were experienced people. You must all of you have realized that the project manager said 'It is impossible'. No software project goes without problems." She could give me no explanation at all to the decision. A piquant detail is, that just this manager had complained to me previously about the impossible time-schedules imposed by the sales department. In this case, I raised a non-conformance against 4.2 "Contract review", because the review had not ensured that the delivery-date requirement could be met.
The paragraph in ISO 9001 about "Contract review" is intended to ensure that the supplier checks before contract that the organization will be able to perform what is required by the contract. This shall be done by having those responsible for the actual work (e.g. the development managers) review the contract or the tender and document their acceptance or objections. Typical examples of what an auditor would ask:
- Are the requirements documented and understood?
- Are acceptance criteria included?
- Have requirements differing from the tender been resolved?
- Can the supplier muster enough resources for the contract?
- Can the supplier muster the competence needed for the contract?
- Can the task be completed in time?
The standard does not require the supplier to have the required resources and competence available at contract review. For example, it would then be difficult to issue several tenders, not expecting to win all of them. However, an auditor would expect that contract review covers such contingencies. For example, if the supplier were to win all contracts, can parts be subcontracted?
The standard requires that there be a documented procedure for contract review, and that such reviews be recorded. Further, the standard requires the supplier to identify how contract amendments are made. An auditor would also expect that in projects the handling of the requirements specification between supplier and customer be defined.
Design control (4.4)
The quality element "Design control" is important for software development, since so much of software development is design. Basically, the requirements are that the development be planned, controlled and verified. It is a remarkably common failure in many software organizations, that software development is conducted in an informal way. Some basic sentiments in 4.4 may be summarized in these two statements:
- If something is not planned, there is no reason to expect it to happen.
- If you do not specify what is to be achieved, there is no reason to expect it to be achieved.
The following are subclauses of paragraph 4.4 in the standard.
This is a cover clause, which says that the supplier should have and use documented procedures to control and verify the design, so that the requirements are met. ISO 9001 requires you to plan before doing, and specify before designing.
General slackness in the design work could be noted by an auditor through reference to this paragraph.
An auditor would expect to find procedures and standards for design, coding and testing. The level of detail in standards may differ considerably between organizations, however. Also, there is a trade-off between standards and reviewing. For example, I sometimes find detailed rules about how to structure source code. Sometimes one might get a better result by having more general rules, and then check on understandability and modifiability during reviews o the code.
Design and development planning
The supplier is required to plan design and development activities. In this context, a time schedule does not constitute anything close to a plan. ISO 9000-3 refers to two plans: A development plan and a quality plan
A development plan should contain the following:
- A definition of the process or methodology to be used in progressing from the purchaser's requirements to a software product.
- Description of the organization and management of the project. Time schedule, responsibilities, work assignments and progress control should be covered.
- Description of the phases, work packages or any other units the supplier will divide the project into. This should include input, output and verification of output. An auditor would probably not accept a development process, where significant intermediate work products were not subject to testing and/or review.
- Description of methods and tools to be used in development.
- The quality plan covers acceptance criteria, reviews, tests, configuration management, change control and error handling. The quality plan should contain:
- Quality targets
- Criteria for the acceptability of input to and output from phases, work packages etc.
- Identification and planning of the tests and reviews and other verification and validation activities in the project.
- Specific responsibilities for quality activities.
Neither the development plan nor the quality plan have to contain all information. In practice, such plans usually refer to existing procedures and internal standards.
The concept of a quality plan comes from the manufacturing industry, where the production is an ongoing activity, for example with steel entered in one end of a production line, and bolts and nuts coming out in the other end, day after day. The production line activities do not need a specific plan, but quality assurance needs one. Thus, there will be a quality plan prescribing quality activities such as sampling, audits etc.
Software development, however, is run in projects which need planning anyhow. Therefore, at least for small software projects, often there is no specific quality plan. A "program development plan" or "project plan" covers all activities in the project, including the specific quality assurance activities.
The development plan and the quality plan are important from the point of view of the quality system. If an organization makes detailed prescriptions for software development in a common set of procedures, there will probably be projects for which the procedures should be modified. Other organizations have common procedures on a high level only, and require each project to decide on the detailed procedures. In both cases, the project plan is where to describe (or reference) the project-specific procedures. When the plans are approved by whoever is the internal "owner" of the project, the specific quality system modifications and additions for the project are also approved.
Now, an interesting question usually pops up: Can we have a very brief company quality system, which only says that the projects will choose their own way of working and managing quality? Yes, we can, if we only want a specific project to fulfill ISO 9001. No, we can't, if we want the company quality system to fulfill ISO 9001. When a company is certified to ISO 9001, the certificate is not about a specific project, it is about the company as a whole.
Organizational and technical interfaces
If the design work is done by more than one group, the standard requires that the organizational and technical interfaces between them be identified and documented and transmitted to those needing the information. To ensure that the interface documentation is kept up to date as the design progresses, the interface documentation shall be reviewed regularly.
The development plan is a good place to describe interfaces between groups. Most larger software projects have milestone meetings when finishing project phases. Usually, the development plan is reviewed at such meetings, and then this specific requirement in the standard is met.
In software development, one type of design input is some kind of requirements specification. This may either be furnished by the purchaser or prepared by the supplier based on the contract requirements and, when applicable, laws and other "statutory and regulatory requirements". Another kind of design input are design documents used as input to coding.
The requirement in the standard is basically that the requirements and design be documented and under formal change control before they are used as input to any activity. This will be a significant change in how many software organizations operate; this kind of strict formalization often seems unnecessary. The background is of course that the standard wants to ensure that the work product of each step meets what is required of it. To ensure this, one must be sure that all changes in the basis for the work will be included in the result. "But it works very well for us without having specifications under early change control", you perhaps say. Fine, by all means continue that way if you want to. But don't seek ISO 9001 certification. For that, your organization needs to be able to convince an external auditor that your way of work will continue to work OK. See section 4.4 for a discussion on prototyping, though.
However, some software organizations try to squeeze calendar time by doing as much work as possible in parallel. This tends to lead to project members using preliminary versions of specifications as basis for their work. Formally, this is a non-conformance with the standard, but a competent auditor will accept such a procedure, if he/she can see that the work result eventually will be in accordance with the final version of specification. For example, there might be a specific review of the final work result to ensure that it meets the final version of the spec.
Para 4.3.3 in the standard requires that there be a procedure for contract amendments. In software development, requirement changes are common, so there must be a procedure for handling new and changed requirements from the purchaser.
In software development, design output is both the design documentation and the source code. The standard requires the design documents and the source code to be reviewed before release for subsequent use.
There shall be a process for acceptance of the design output, and the criteria for acceptance shall be defined. This is not as complicated as it looks. For example, the review might be the process for acceptance, and the criterion would be acceptance by the review team.
Formal, documented technical reviews of design results shall be planned and conducted. The review team shall include sufficient competence. The project functions (e.g. coding, testing), for which the result under review is important, shall be represented at the review.
This is an area where I have noted many non-conformances. Software engineers say: "But we do review everything. It's only that our reviews are informal. Do we really have to plan them and write minutes of meeting? That would not make our reviews more efficient." But it would. In the long run, informal reviews will deteriorate. With hard pressure for time, personal disagreements and all other disturbances, informal reviewing will soon become sporadic and inefficient. This is not to say that there should not be informal reviews. Colleagues helping each other by reading each other's work results is a very good way to work. But in order to rely on reviews, both the supplier management, the customers and possibly a certification body must see that the reviews take place and what they achieve.
Once, I was auditing a company, and I began to suspect that their reviewing activities were just formalities, which found only simple formal errors. I then had a look at the documentation of errors found in system testing. I picked one error and asked: "Why was not this error found in a review?" The supplier's representatives hummed a bit, but at last they agreed that they would have to do something about their reviewing. In this way, it is possible to find out if the reviewing works; but still, the auditor would need documentation of the reviews.
A common method to ensure that reviews actually look into what they should, is to issue checklists to be used by reviewers. The checklists remind the reviewers what they should give special attention, but the checklists have another important function. If the used checklists are included in the review report, it is possible to see afterwards, what the review checked. Usually, when something should be improved in software development, one part of the improvement is the addition of further points to some checklist.
Examples of non-conformances to this part of the standard include:
- No procedure for formal reviews
- No follow-up of correction of errors found in reviews.
The design documentation and the code shall at appropriate stages be subject to reviews and/or tests to verify that they meet the requirements. The paragraph 4.10 "Inspection and testing" in ISO 9001 is also about testing, but it is usually used regarding final testing only.
Design verification usually consists of reviews (see above), module testing and integration testing. Sometimes, developers want to keep verification informal. "Errors are caught in system testing anyhow", they say. Forget it. If your quality policy says that you have the ambition to produce quality products, you have to use all available means to catch design errors.
The supplier shall conduct a specific activity to ensure that the final software product conforms to requirements. Normally, this activity is a final system test of the complete software product. However, reviewing may also be included, for example of user documentation. This is an overlap with paragraph 4.10 "Inspection and testing" in the standard.
Validation shall be a planned and documented process. Sometimes, it is up to the individual tester, how to test and what to do about errors. I recently visited a supplier of control systems for cars. Very often their testing consisted of an employee borrowing a car during the weekend. When driving, he/she was then required to note all disturbances. It is possible that in specific cases, this would be the appropriate way to test, but then an auditor would expect to find this decision explicitly made and documented.
"Our testing is sufficient. If something is wrong, the customers will notice in their own testing." This is the wrong thing to say to an ISO 9001 auditor. The supplier is assumed to be responsible for product quality. However, the customers sometimes explicitely take on the task of helping the supplier with beta testing. This can not be faulted by an ISO 9001 auditor, as long as the beta testing is covered by a clear agreement between the supplier and the beta-testing customer.
There are usually a lot of changes to specifications and code, both during initial development and during the maintenance phase. Since software is so complex, changes may be dangerous for the following reasons:
- The introduced modification does perhaps not lead to the required change in the product.
- Changes often introduce errors in the software.
- A modification of the software may disrupt the "architecture" of the software, thus making later modifications more difficult and error-prone.
- There is a risk for specifications and code to diverge because of changes in one but not the other. After a while, specifications may be of no use for further modifications. Of course, the source code is sometimes expected to diverge from some early documents. Such documents can be viewed as tools for thought during the project, and finished, they have value as reference material only. What documentation actually is maintained may differ between different development models; an auditor will make a judgement whether sufficient documentation is under change control.
This means that anyone trying to judge the software development process of a supplier will definitely want to see that modification activities are properly controlled.
ISO 9001 requires that after the release of a design document or a source program, all changes of it shall be through a formal process whereby the changes are documented, reviewed and approved before implementation.
The standard does not explicitly say when a document or program shall be released. Some suppliers try to avoid a cumbersome change process by saying that requirements and design documents will not be released until a late point in the project, e.g. after final test. Thus, they think, if for example a programmer finds an error in the design document he or she is using as input, anyone can correct the error immediately without much ado.
However, uncontrolled changes to complex technical documents or programs are extremely dangerous, and as we saw in 18.104.22.168, the standard does not allow it. Modifications and error corrections are tricky and dangerous operations, so ISO 9001 requires a formal, cumbersome modification procedure, just in order to slow the process down and ensure that it is handled correctly.
Document and data control (4.5)
For us, "documents and data" means information which in some way controls the development or maintenance of software. Examples of such documents are:
- Requirements specifications
- Design documents
- Source code files
- Work procedures
- Internal and external standards
Briefly, the standard requires that those who need some document or some data shall have access to it, and they shall be using the appropriate version. Changes to documents and data shall be controlled.
The supplier shall use documented procedures to control documents and data. Also external documents, e.g. customer documents, contract, programming language manuals, shall be under control. Both documents and data can be on any form of media, e.g. hard copy or electronic media.
When auditing against ISO 9001, I frequently raise non-conformance to 4.5 "Document and data control". Typical non-conformances are:
- Someone is using a document which should be approved, but is not.
- Somebody uses the wrong version of a specification or a plan.
- I find two documents with the same identity and the same version number, but different contents.
- Someone using a document can not explain how he/she knows that the document is the appropriate version.
- Someone needing e.g. a plan for his/her work, does not have easy access to it.
Document and data approval and issue
The documents and data shall be reviewed and approved before issue. For paper originals, this is usually indicated through signatures on the documents. When the original is stored electronically, one might use separate document lists, where the appropriate version of a document is signed off to indicate review and approval. There are also cases where "electronic signatures" are used. Document control procedures and/or tools then ensure that signatures are not entered by mistake.
The standard anyhow requires the supplier to maintain a document list (or a procedure), whereby one easily can find out which is the current version of any document.
The document control procedures shall ensure that pertinent issues of documents are available everywhere where they are needed. This is not so difficult, but the next requirement is: The document control procedures shall ensure that all invalid and/or obsolete documents are removed from use or clearly marked.
In a manufacturing industry, there are relatively few documents. If a new version of a procedure or a drawing is issued, someone can walk around with the new version and physically withdraw the old version at all places where it is used.
In software development we have many documents, and they frequently change. Still, we need to know that people use the right versions of all documents. A popular way to achieve this in the software industry is to put all procedures, specifications, programs etc on the computer network and have people read them from the screen rather than each having their own paper copy. This works if it is easy enough to find documents and read them on-line. Otherwise, people will print out their own paper copies and we don't know if they are using the proper version.
Other methods are:
- Distribution lists for all documents, so that all users get the new versions. Users are instructed to destroy or mark the old version.
- Prominent publication of the fact that a document has been changed, combined with a requirement on people to furnish themselves with the new version and destroy or mark the old one.
Whichever method the supplier is using, the important thing is whether it works. When auditing, I usually ask the persons I interview to show me the documents they are using.
Document and data changes
When a document or some data is changed, it shall be clear who shall review and approve the change. If it is practicable, a description of the change shall be included in the document or prepared as an attachment.
A few years ago, an English company had won a large order for some complex, computer-controlled equipment. The contract contained a comprehensive set of requirements on the supplier's software development, including the fulfillment of ISO 9001. In the beginning of the contract, I was employed by the customer to conduct an audit of the supplier to ensure that their plans and processes for software development were OK. I planned to spend two days at the supplier's premises, and I sent them a rough audit program for those days, which they accepted.
Then I arrived together with the customer's representative, and we met with some of the managers in a conference room. They were very glad to meet us, but they did not have any software development at all. They had subcontracted it to a company in Australia, and their happy faces indicated that they did not have a care in the world.
"So", I said, "but you are still responsible for the quality of the product and the timeliness of your delivery?" "Ye-es", came the answer from a not so confident manager. "Well then, will the quality of the software be sufficient and will it be finished on time?" I asked. This time, the affirmative answer was even more hesitating. Then I went in for the kill: "Convince me!" i said.
It took all of the two days. Finally, the supplier's managers realized that when you subcontract software development from a distant subcontractor, you have an even more difficult situation than if you were to develop the software inside your own organization. They had to plan for a number of activities:
- Journeys to Australia to audit the subcontractor's software development,
- Their own review of the subcontractor's plans, specifications and code,
- A system for distributing modified requirements to the subcontractor,
- Procedures and criteria for acceptance of the software,
- Configuration management and maintenance of the software delivered from the subcontractor.
Paragraph 4.6 in ISO 9001 specifies requirements on purchasing. A peculiarity with ISO 9001 is that even if a supplier is bound by the contract to fulfill ISO 9001, the ISO 9001 requirements don't have to be imposed on the subcontractors. Instead, paragraph 4.6 in the standard contains requirements on how to control subcontractors. The following describes some of the subparagraphs of 4.6. "Supplier" denotes the organization on which the standard puts requirements. "Subcontractor" is the organization from which the supplier purchases software, hardware or services.
As usual, the supplier shall follow documented procedures. It shall be ensured that purchased products conform to requirements. Notice that the requirements in 4.6 are not about the purchase of pencils and erasers, they are about parts of the product and tools which may affect product quality. A special case is the purchase of services. Sometimes, suppliers are not clear if they are hiring consultants to help them with development, or if they are purchasing the development of a certain item. If you purchase manpower only, the standard only requires you to follow a procedure for ensuring that you get the right people. The work done by these people will be controlled directly by the supplier, not the subcontractor.
How do we ensure that purchased software conforms to requirements? It depends on the type of software and its importance, but usually some or all of the following is used:
- Contract requirements on the subcontractor's procedures
- Audits of the subcontractor's quality system
- Checking the subcontractor's past performance
- Surveillance of the subcontractor during the contract
- Witnessing reviews and testing
- Test and review of deliverables from the subcontractor
Evaluation of subcontractors
The supplier shall evaluate all subcontractors. This means that someone with the necessary authority and competence shall judge each subcontractor and decide whether to use that one. This decision and its rationale shall be documented.
When using a subcontractor, the supplier shall decide what control is to be exercised over the subcontractor. Notice that the standard does not say how much control to impose. The requirement is that the supplier make a decision based on relevant facts. For a subcontractor developing software, the amount of control may vary, depending for example on the subcontractor's past performance and the importance of the subcontracted item. Examples of control options are
- regular audits of the subcontractors quality system and its application
- review of the subcontractor's plans
- witnessing of the subcontractor's reviews and tests
- Supplier approval of individual work results (for example plans, specifications, code or test results) as they are produced by the subcontractor.
A special case is when the software is purchased through retail. In this case, the "subcontractor" is the organization with which the purchase is conducted, not the original developer of the software. In such a case, it is formally the retailer's responsibility to control its subcontractor. However, sometimes the buyer still requires access to the developing organization in order to be able to evaluate its quality system. Of course, in the case of off-the-shelf software products which are in extensive use in the market, the need and opportunity for explicit control may be small. If you are purchasing software through retail, ISO 9001 requires that you define to what extent you put requirements on the retailer to control its supplier.
The supplier shall maintain a list of acceptable subcontractors.
The items subcontracted or purchased shall be well specified. Requirements on the subcontractor's development process shall be documented in the contract, as shall requirements for the supplier to approve work results and procedures.
Before purchase, the purchasing data shall be reviewed by the supplier.
Verification of purchased product
The auditor will expect to find documentation of a decision about the verification of each purchased development tool or included product. There are several different cases to consider.
- A tool supporting the development or validation of software is purchased. The quality of the tool does not influence the quality of the supplier's product or the quality of the service to the customer. In this case, the decision may be to do no verification.
- A tool or included product is purchased, which is an off the shelf item and has been used extensively by other suppliers for some time. Examples are compilers and operating systems. In this case, the decision may be to view the item as a "proven design" and do no or little verification. Notice, however, that extensive use of older versions of the tool or included product may be insufficient evidence of "proven design".
- The purchase concerns development and production of some new hardware or software. In this case, a reasonable decision may be to put requirements on the subcontractor's development and production (including testing), and to check that these requirements are fulfilled. Witnessing of the subcontractor's testing and/or the supplier performing specific acceptance testing may be appropriate.
- A tool or included product is purchased, which is already developed and produced, but which has not been extensively used. An example may be an operating system version for a new type of processor board. In this case, the supplier has to become convinced that this purchased product meets the requirements. In this case the verification may include collection of the experiences of other users, as well as extensive testing.
Examples of common non-conformances with 4.6 include:
- No list of approved suppliers
- inappropriate control of subcontractor
- no documented verification of purchased items
- inappropriate contract with subcontractor.
Control of customer-supplied product (4.7)
Once, I encountered a situation, which puzzled me at first. The customer used two suppliers to deliver each their own part of the product. Supplier A developed some basic software which was also included in the software developed by supplier B. The software was delivered directly from A to B. The question was: Who was responsible for the functioning of A:s software inside B:s products? Surprisingly, the answer was: The customer! It was the customer who required B to use software from A, so the formal way to look at the relations was that the customer first purchased the basic software from A and then delivered it to B. Paragraph 4.7 in ISO 9001 covers such situations, where the customer supplies software to be included in the product.
The standard says that the supplier shall have procedures for verification, storage and maintenance of customer-supplied software. However, the quality of this software is the responsibility of the customer.
An auditor would expect the supplier to have procedures for identification, version handling and error reporting for customer-supplied software.
Notice that even if the customer requires two suppliers to cooperate regarding software developed by one and included by the other, the ultimate responsibility lies with the customer. Unclear division of responsibility between customer and supplier is a common non-conformance to this paragraph in the standard.
Product identification and traceability (4.8)
This paragraph is used to make the software supplier to keep control of such issues as:
- For each software specification, what preceding document and issue is it based on?
- For each source code module and design document, which specification(s) is it based on?
- What error corrections and amendments have been included in what source programs?
- What happened to each problem report? What decisions were made, what changes, what testing etc?
- From what source program versions was a specific load module generated?
The auditor may very well bring out the identity of a certain item and ask a manager: "How do you know that this item is the correct version?" The auditor would not expect the manager to have checked this specific item. Rather, an appropriate answer might be something like: "Our procedure XYZ-123 ensures that all items of this kind have the right version. In our internal audits, we have checked that the procedure is adhered to. If you like, we could go to the development library and trace this item to its requirements."
It is surprising how often I have found deficiencies in this area when auditing. Examples are:
- Wrong version of a source file in a library.
- A change was reported as introduced, but was not.
- A manager or project leader was unable to show what source code versions were used in system test.
- Insufficient traceability for change requests.
Process control (4.9)
This paragraph covers general requirements on the control of production, installation and servicing. For software, the paragraph is used for requirements on the control of replication and installation. Replication is the process of writing to a diskette, tape, PROM or other medium, the load module(s) and data to be delivered.
The auditor would expect to find in operation a documented procedure for the replication process. Also, he/she would look for a procedure for the handling of master PROMs or master libraries, to ensure that the correct versions are always used.
Non-conformances raised against this paragraph of the standard frequently include
- No documented procedure for replication,
- improper handling of master PROMs or diskettes.
Inspection and testing (4.10)
Since ISO 9001 was written for manufacturing industry, paragraph 4.10 is aimed at inspection and testing of produced goods.
Thus, we use this paragraph for requirements on the inspection and testing done in connection with replication. The auditor expects to find written procedures for what inspection and testing to be done at replication. What makes the supplier confident that the software is replicated correctly and from the correct version of the master software?
Especially if the replication process includes compilation, linking and/or parameterization, it is important that there be appropriate procedures in operation.
Typical non-conformances in this area are:
- The equipment for programming PROMs also check on the result. The function of this automatic check has not been checked regularly.
- No documented procedure for testing of PROMs.
Inspection and testing during development is covered in ISO 9001 paragraph 4.4.7 under "design verification". Final testing is covered in paragraph 4.4.8 under "design validation". Some auditors may, however, also use paragraph 4.10 in the standard for requirements on final testing of software.
Control of inspection, measuring and test equipment (4.11)
This paragraph mainly covers requirements on the calibration of measuring equipment. In software development we do not usually have much measuring equipment which needs calibration. Possible examples may be:
- Clocks for testing timing requirements
- Voltmeters for testing programs which operate D/A-converters.
- Line analyzers
Estimation methods may need calibration. Often, estimations are based on typical values experienced in earlier projects. These values must be checked as time goes by, to ensure that they are still appropriate.
The standard requires that the supplier select the appropriate measuring equipment and follow a documented procedure for the control of this equipment. There shall be a list of all instruments needing calibration. The instruments shall be calibrated at prescribed intervals, and they shall be marked with calibration status.
Apart from measuring equipment, paragraph 4.11 in the standard also covers test tools. For example, if you use a test data generator, then you have to check regularly that it generates the right test cases. This regular check is required even if your tool is software and does not wear down. Your types of applications and your way of testing may vary and make the testing tool less appropriate. Also, this paragraph in the standard may be used as a requirement that each new version of a software tool for testing be checked for sufficiency.
Inspection and test status (4.12)
ISO 9001 requires that specifications and programs be verified, usually through reviews and/or testing. The supplier shall have procedures that preclude the use of unverified specifications or programs.
An auditor will expect to see that
- It is easy to ascertain whether a certain item has been reviewed, tested, and approved. Usually, this is achieved by the maintenance of a list of specifications and source programs with their current status.
- Unverified specifications and programs are kept apart from verified items, e.g. in a different directory.
A typical non-conformance is when somebody is using a specification and does not know that it has been approved.
Control of nonconforming product (4.13)
A non-conforming product is a specification or a program, which either does not fulfil the requirements or has not been developed in accordance with prescribed procedures.
Paragraph 4.13 requires that the supplier have procedures to ensure that non-conforming products not unintentionally be used. For software, this means that the auditor will look for
Clear identification of controlled items which contain uncorrected errors. Of course, during the preparation of a document or program, it will be incorrect most of the time. However, it can not become a nonconforming product until it is in some way "frozen".
A method to elicit customer acceptance of delivery of nonconforming software, for example in the case of a pre-release.
In some cases, there is a need for emergency modification of software. Either, the organization operating the software must for their business be able to get quick changes every now and then; or perhaps a critical error might pop up in an important computer application. In these cases, there is sometimes not time to apply the ordinary rigorous development procedures. "Control of non-conforming product" in this case means that
- an auditor would expect to find a procedure for handling quick modifications,
- the fact must be documented that the modified specifications and source programs have not been handled in the normal way,
- it must be possible to see that afterwards, the modified items will always be elevated to the same status as the rest of the software, for example through specific reviewing.
A non-conformance would be raised against paragraph 4.13 in the standard, if it were unclear which documents and programs contain detected errors.
Corrective and preventive action (4.14)
ISO 9001 is not strong regarding requirements for continuing improvement of the supplier's work processes and product quality. This is perhaps natural, since the standard was originally intended for use in single contracts. If we as customers meet this supplier in only one acquisition, we are not very interested in the long-term improvements. Those will only benefit other customers.
However, paragraph 4.14 contains some requirements for "self-sharpening" of the software development process. The paragraph contains requirements on the improvement of products as well.
Basically, the paragraph contains three requirements:
- The effective handling of customer complaints and other reports indicating that the software product does not conform to requirements
- The effective handling of audit reports and other information indicating shortcomings in the development process
- The active collection and analysis of available information about product and process non-conformance, and the proper actions to prevent problems in other software.
The first requirement concerns normal correction of errors reported from customers, and this is not difficult to make software developers and managers understand. However, I frequently find it difficult to make software managers understand the implications of the last two. Let me try to explain.
The idea of ISO 9001 paragraph 4.14 is that information about encountered problems should be a driver for improvements of the development process. If a weakness is found in the process, an improvement action shall be taken as soon as possible. When errors are found in the software, aside from the immediate correction of the errors, there shall be conducted an analysis of the root causes. If possible, actions shall then be taken to improve the process to prevent recurrence of these specific types of errors.
A common way to handle the root cause analysis is to have a group of persons to meet, for example every third month, to review all reports from design and code reviews, testing, customer complaints and quality audits together with complaints and improvement suggestions from the staff. If the group finds that something shall be done, a corrective action is initiated in the same way as corrective actions prompted by quality audits. Then, there is a regular follow-up of the progress of all corrective actions.
Auditors frequently find serious non-conformances to this paragraph in ISO 9001. A few examples:
- A customer complaint has not been properly handled
- A deficiency has been found in an internal quality audit, but not been corrected
- There is no procedure to ensure that all problems be analyzed and acted upon
- There is no procedure for reporting difficulties with applying rules and procedures.
Handling, storage, packaging, preservation and delivery (4.15)
This paragraph is about handling etc of produced goods. Thus, we apply it to software which is replicated and sitting in a PROM, diskette or other medium. We also use the paragraph for requirements on the handling of finished software which is kept in repository (e.g. product libraries), either for use as masters when replicating, to be used when modifying the software product, or to be reused in new products.
The supplier shall use procedures for the handling and storage of software media, so that damage and deterioration is prevented. For example, magnetic media shall be refreshed at regular intervals. Media shall be labelled and packed appropriately.
Repositories for software (including data and tools) shall be backed up. The repositories shall be protected for unintentional damage, e.g. through access limitations. This last point may for example have to do with our deplorable tendency to do hurried unauthorized changes.
Even if there is a strict formal process for how to modify software, there is the risk for spontaneous changes. Imagine that you are a programmer in a project. Your program has been reviewed and approved and put under formal change control. The day after the review, you suddenly become aware of an embarrassing minor error in your program. The natural action is to quickly make a simple modification of the program original, without anyone noticing. The risk is, however, that in your haste, you botch the modification, or by introducing this change you affect some completely different function in the program without noticing.
To ensure against this type of spontaneous changes, an organization should see to it that programs and specifications which are put under formal change control, are stored with some access restrictions.
Control of quality records (4.16)
When purchasing complex software products to be developed by a supplier, the customer needs confidence in the delivered product. Basically, there are three means for the customer to achieve this confidence:
- Past performance. The customer will check on the supplier's success with previous undertakings.
- The customer's own testing of the software.
- The customer's insight into the supplier's development process.
As software products grow more complex, customers have to rely more on the last alternative. During development and maintenance, the customer will require opportunities to see what is happening. The most important source for information about the effectiveness of the software development process are quality records. Quality records are documents which show that actions have been taken, which ensure or check quality. Examples of quality records are:
- Minutes from management review
- Minutes from contract review
- Records of reviews of specifications and programs
- Records of the follow-up of review remarks
- Records of subcontractor evaluations
- Records of all reported errors from report to clearance.
- Quality audit reports
- Test plans and reports
- Documentation of corrective actions
- Purchasing documentation
The standard requires that there be a procedure for the handling of quality records. The records shall be safely stored and easily accessible. After a specified period after the end of the project, quality records shall be disposed of.
Typical non-conformances are:
- Lack of rules for the retention of quality records
- Review records are not kept
- Test records are not kept
- The period for keeping quality records is not defined.
Internal quality audits (4.17)
A certified supplier is audited regularly by the certification body. This is not enough. The supplier shall also have an independent part of the organization audit regularly all operations which may affect product or service quality.
Such internal quality audits shall investigate
- whether the work performed in software development adheres to plans and procedures
- whether the quality system is effective, i.e. that existing procedures etc are the right ones.
Internal quality audits are conducted on behalf of company management. The auditor or auditors must be independent of the operation audited. So, for example, the person auditing a certain department must not be a member of that department. He or she could not audit the department management.
Often, the audits are planned and managed by the company quality manager, who uses persons from different parts of the company to audit each other's departments.
Since software development is usually conducted in projects, quality audits must go into different projects to check on the usefulness of the quality system and on the adherence to it. Such audits are called "project audits". Other aspects of the company are best audited by focussing on what lies outside projects, e.g. line management, corrective action, training. Such audits are called "quality system audits".
All parts of the quality system shall be audited regularly at specified intervals. Some parts may need to be audited more frequently than others, due to their importance. There shall be an audit plan, which shows what internal audits will be conducted in the near future, usually the next 12-month period. Quality audits shall be planned and reported, and deficiencies found shall be corrected (see 2.14).
Typical non-conformances are:
- No audit plan
- Audit plan not up to date
The standard does not require the supplier to employ good people or excellent technicians. That would not be reasonable or checkable. Instead, the standard requires the supplier to see to it, that the staff are trained for their tasks.
Paragraph 4.18 requires the supplier to have a procedure for
- Identifying training needs for each staff
- Providing such training
- Keeping records of the training of all staff.
In Sweden, much of this is covered by procedures for "career reviews", when managers sit down with each subordinate and go through their work situation, career prospects and different kinds of needs.
Examples of the kind of training an auditor would expect to see planned:
- New programming languages and tools
- Audit training for internal quality auditors
- Project management training
What kind of training should there be? Is it sufficient to let a programmer sit a couple of days with the manual for the new programming language? Well, it is not really up to the auditors to judge your means for training and education. As long as the training is documented and sufficient, the auditor should be satisfied. The criterion for sufficient training is that the person is capable of performing his/her work to a high enough standard. The auditor may se this for example in review records and project success. However, quality auditors and other staff with a need for specific qualifications should be able to produce records of formal training.
Typical non-conformances are:
- No procedure for planning of training
- No training records
- Some employee has not received proper training for his/her task.
The standard says that the supplier shall have documented procedures for servicing if this is required in the contract. The standard talks about the repair of delivered items, e.g. sending somebody out to repair a faulty refrigerator.
In the software business, this paragraph is about maintenance, i.e. error corrections and enhancements to delivered software. Paragraph 4.14 "Corrective and preventive action" requires the supplier to have a way to receive customer complaints. Using paragraph 4.19, the auditor requires the supplier to have procedures for the rest of the handling of complaints and requests for modifications. The supplier can avoid these requirements only if there is no maintenance contract, and if there are no warranty commitments.
Since software maintenance is very similar to the initial development on the technical level, most of the requirements in paragraph 4.4 - 4.13 apply as well.
A common concern among software suppliers searching to fulfill ISO 9001 is regarding the maintenance of old software. Typically, the current software development follows a well-defined process with some specific types of documents being produced. These documents do not exist for old software, so the old software can not be maintained in accordance with the brand new procedures. The solution is to have specific procedures for maintenance of old software. These procedures might best be documented in maintenance plans for the different software products. The auditor will only expect to see that the maintenance is under control.
Typical non-conformances are:
Maintenance work for a customer without a contract
- Specific methods for maintenance of an old product are not documented
- No procedure for testing after maintenance activities.
Statistical techniques (4.20)
Statistical techniques are important when the quality of e.g. bolts and nuts is checked through sampling. Paragraph 4.20 is about such checks.
However, for software the paragraph is interpreted as a requirement that the supplier measure the quality of both the products and the development process.
The auditor will look for collection and analysis of data about number of found errors in different phases, as well as ability to meet deadlines and milestones.
As an auditor, I would ask: "How many errors do you find during system test, and how many errors do your customers find for you?" Difficulties to answer that question would lead to a non-conformance.