Why is it often hard for management to get serious
about quality assurance?
Solving problems is a high-visibility process;
preventing problems is low-visibility. This is
illustrated by an old parable:
In ancient China there was a family of healers, one of
whom was known throughout the land and employed as a
physician to a great lord. The physician was asked which
of his family was the most skillful healer. He replied,
"I tend to the sick and dying with drastic and dramatic
treatments, and on occasion someone is cured and my name
gets out among the lords."
"My elder brother cures sickness when it just begins to
take root, and his skills are known among the local
peasants and neighbors."
"My eldest brother is able to sense the spirit of
sickness and eradicate it before it takes form. His name
is unknown outside our home."
Why does software have bugs?
• miscommunication or no communication - as to specifics
of what an application should or shouldn't do (the
• software complexity - the complexity of current
software applications can be difficult to comprehend for
anyone without experience in modern-day software
development. Windows-type interfaces, client-server and
distributed applications, data communications, enormous
relational databases, and sheer size of applications
have all contributed to the exponential growth in
software/system complexity. And the use of
object-oriented techniques can complicate instead of
simplify a project unless it is well-engineered.
• programming errors - programmers, like anyone else,
can make mistakes.
• changing requirements (whether documented or
undocumented) - the customer may not understand the
effects of changes, or may understand and request them
anyway - redesign, rescheduling of engineers, effects on
other projects, work already completed that may have to
be redone or thrown out, hardware requirements that may
be affected, etc. If there are many minor changes or any
major changes, known and unknown dependencies among
parts of the project are likely to interact and cause
problems, and the complexity of coordinating changes may
result in errors. Enthusiasm of engineering staff may be
affected. In some fast-changing business environments,
continuously modified requirements may be a fact of
life. In this case, management must understand the
resulting risks, and QA and test engineers must adapt
and plan for continuous extensive testing to keep the
inevitable bugs from running out of control - see 'What
can be done if requirements are changing continuously?'
in Part 2 of the FAQ.
• time pressures - scheduling of software projects is
difficult at best, often requiring a lot of guesswork.
When deadlines loom and the crunch comes, mistakes will
• egos - people prefer to say things like:
'piece of cake'
'I can whip that out in a few hours'
'it should be easy to update that old code'
'that adds a lot of complexity and we could end up
making a lot of mistakes'
'we have no idea if we can do that; we'll wing it'
'I can't estimate how long it will take, until I
take a close look at it'
'we can't figure out what that old spaghetti code
did in the first place'
If there are too many unrealistic 'no problem's', the
result is bugs.
• poorly documented code - it's tough to maintain and
modify code that is badly written or poorly documented;
the result is bugs. In many organizations management
provides no incentive for programmers to document their
code or write clear, understandable, maintainable code.
In fact, it's usually the opposite: they get points
mostly for quickly turning out code, and there's job
security if nobody else can understand it ('if it was
hard to write, it should be hard to read').
• software development tools - visual tools, class
libraries, compilers, scripting tools, etc. often
introduce their own bugs or are poorly documented,
resulting in added bugs.
How can new Software QA processes be introduced in an
• A lot depends on the size of the organization and the
risks involved. For large organizations with high-risk
(in terms of lives or property) projects, serious
management buy-in is required and a formalized QA
process is necessary.
• Where the risk is lower, management and organizational
buy-in and QA implementation may be a slower,
step-at-a-time process. QA processes should be balanced
with productivity so as to keep bureaucracy from getting
out of hand.
• For small groups or projects, a more ad-hoc process
may be appropriate, depending on the type of customers
and projects. A lot will depend on team leads or
managers, feedback to developers, and ensuring adequate
communications among customers, managers, developers,
• The most value for effort will be in (a) requirements
management processes, with a goal of clear, complete,
testable requirement specifications embodied in
requirements or design documentation and (b) design
inspections and code inspections.
What is verification? validation?
Verification typically involves reviews and meetings to
evaluate documents, plans, code, requirements, and
specifications. This can be done with checklists, issues
lists, walkthroughs, and inspection meetings. Validation
typically involves actual testing and takes place after
verifications are completed. The term 'IV & V' refers to
Independent Verification and Validation.
What is a 'walkthrough'?
A 'walkthrough' is an informal meeting for evaluation or
informational purposes. Little or no preparation is
What's an 'inspection'?
An inspection is more formalized than a 'walkthrough',
typically with 3-8 people including a moderator, reader,
and a recorder to take notes. The subject of the
inspection is typically a document such as a
requirements spec or a test plan, and the purpose is to
find problems and see what's missing, not to fix
anything. Attendees should prepare for this type of
meeting by reading thru the document; most problems will
be found during this preparation. The result of the
inspection meeting should be a written report. Thorough
preparation for inspections is difficult, painstaking
work, but is one of the most cost effective methods of
ensuring quality. Employees who are most skilled at
inspections are like the 'eldest brother' in the parable
in 'Why is it often hard for management to get serious
about quality assurance?'. Their skill may have low
visibility but they are extremely valuable to any
software development organization, since bug prevention
is far more cost-effective than bug detection.
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