[continued from Development environment]

Expanding our repertoire

Most development environments include a debugger, which is an essential tool for producing quality software. However, the function of a debugger goes well beyond merely helping to find bugs. Some programmers do not regularly use a debugger, or only use one to help locate “that tough bug.” If you fall into this category, I strongly urge you to familiarize yourself with a debugger and integrate it into your standard development process.

Using a debugger for code assurance is another form of glass box testing. It is most powerful when used to perform live walkthroughs of program code. You can manually step through your code, examining variables, and make sure that it is performing as expected. There is no better way to assure yourself that the program is performing correctly than to actually watch it. It also helps identify situations where an errant value could cause problems.

To put this capability to work for you, set a breakpoint at the beginning of each new routine. When the breakpoint triggers, step through the code line by line, confirming that the variables are correct and that the process produces the desired results. Some authorities recommend setting a breakpoint at every single code path, only removing a breakpoint when the path has been thoroughly tested. I must admit that I find this to be overkill in some situations, such as where the function is simply returning an error code, but I do this for all significant branches.

Another glass box testing tool that is often provided with common development environments is a profiler. A profiler is a tool that takes time measurements of a running application and then provides performance statistics for modules or specific functions. This is useful for identifying performance bottlenecks and functional irregularities in a program.

There are two important metrics provided by most profilers, function time and execution count. The function time shows how much overall time was spent in a function (or module), which gives an indication of where any performance delays may be. The execution count shows how many times a function was called, and occasionally this highlights an unexpected problem if a routine is being called too often.

Together, the time and count metrics help show where a program can benefit from optimization, and it is useful to have this information. However, unless there is a serious problem, it is best to wait until all program functionality is complete before attempting to optimize. There is a term in the industry for unnecessarily modifying code for performance before having functionality: “premature optimization”.

There are more powerful profilers and debuggers available from third-party suppliers, but I recommend getting comfortable with the capabilities and features, as well as drawbacks, of the tools provided by your compiler vendor before evaluating expensive alternatives. The quality improvement to be gained by using any debugger far outweighs the incremental benefit of switching to a more powerful tool.

[continued in Beyond the build]

[continued from Quality: The Process, Part II]

Development environment

The best place to start a discussion of practical testing is with the development environment and the tools that you are already using. Rather than a comprehensive discussion of programming practices, which would be a book by itself, I will concentrate on using these tools to facilitate the testing work.

Generally, a development environment for a compiled language consists of a text editor, a compiler, and a linker, plus other tools useful during development, and often these are all part of a single IDE (Integrated Development Environment). This compiled development environment is assumed for this discussion, though there are analogous approaches in other environments.

The first step in producing quality code is to understand your development environment. Although there seems to be a growing trend towards hiding or automating functionality, it is nevertheless important to know what the make or project files are doing, and what options are available and being used. You need to how things work in the case that, “It Just Works,” fails.

Assuming you understand how the development environment works, you can begin actually programming. Once a certain amount of code is written, you try to build (i.e., compile and link) the executable. This is, in fact, the most basic form of glass box testing. If there are problems in the source code, or the build environment is not correct, then warnings or errors will be generated.

To make the best use of this functionality, modify the settings in the make or project files to set the highest warning level available. This may produce lots of extras warnings on some projects, but compiler warnings exist for good reasons. A warning almost always indicates that there is an immediate problem or, at least, a lack of clarity within the code that reduces the ease of maintenance and could cause future problems.

Many compilers include an option to treat any warnings as errors, and I recommend enabling this option. Warnings should never be ignored, and this prevents that from happening. Instead, source code should be corrected to eliminate warnings. This may seem like obvious advice to some readers, but my experience working with code from other programmers shows that many programmers routinely ignore warning messages during compilation, a dangerous practice that is contrary to quality development.

Taking this checking one step further, build the program frequently. This allows you to catch the warnings as they are introduced, rather than having a collection of problems at the end of a large coding session. Some warnings indicate problems that may need to be addressed by technical design changes, and it is good to find these problems early. Personally, I rarely write more than a short function between builds.

Black box testing should also be used in the early stages of development, even when features are incomplete. Running the executable regularly helps make sure that errors are not introduced or, when they are, catches them at an early stage. For incomplete features, you can hardcode values for testing, or just assure that the program behaves as expected, considering the missing code.

[continued in Expanding our repertoire]

[This article was originally published in the December 2002 issue of ASPects.]

“Come, give us a taste of your quality.”

When Shakespeare penned these words for Hamlet, he was referring to the calling of those to whom the comment was directed. In this context, quality is literally ones profession. As software developers who, for the most part, can either succeed or fail based on the quality of our work, this interpretation still holds true.

In the first part of this article, I discussed planning for quality software development, classification and tracking of bugs and unimplemented features, and some basic quality assurance concepts and terms. In particular, I explained black box and glass box testing, some methods for which we will explore in this part. As a simple reminder, black box testing is, essentially, user testing of the program itself, while glass box testing is developer testing of both source and object code.

You have been waiting long enough, so it is time to put these ideas into practice.

[continued in Development environment]

[continued from Bug and feature tracking]

More to come

To this point, we have chosen a project, determined what we want to accomplish with the end product, and proved in the design document that we can meet our goals with it. We have recommitted to developing a quality product and we have devised our own system for tracking the features and the bug reports that will inevitably be received, and some of us have even populated the software with features from the design docs.
In short, we have established a strong foundation for quality software development.

Now, all of the real programmers among us are jumping up and down yelling, “Let’s get to the coding already!” With this foundation, we are in a great position to get started with the actual programming. Unfortunately, the discussion of specific glass box and black box techniques, including beta testing methods, will have to wait for the next installment.

I have some coding to do.

Gregg Seelhoff is an independent game developer who serve[d] on the ASP Board of Directors. He can be reached at seelhoff@sophsoft.com.

[continued from Getting started]

Bug and feature tracking

Classification of discovered and reported bugs can be beneficial in determining priorities for development resources. High priority bugs need to be addressed as soon as reasonably possible, while suggestions should probably wait. In my experience, most companies, including Microsoft, use four or five classifications, similar to the following:

1. 1 – Severe error – This includes program crashes, errors which damage data or interfere with the operating system, or anything that prevents further testing. These types of bugs are known as “showstoppers” and, though hopefully infrequent, are urgent issues.
2. 2 – Functionality impaired – This includes any type of bug in which the program does not perform as expected and has a detrimental impact on the ability to use the program.
3. 3 – Minor issue – This includes bugs which are cosmetic, such as spelling errors, or those that do not significantly affect the ability to use the program efficiently.
4. 4 – Suggestion – This includes any suggestions for unplanned and non-essential features. These should generally be implemented only later in development, and changes to address these issues should be reflected in updated design documentation.
5. 5 – Postponed – This includes any suggestions or, in some cases, problematic bug fixes that are not likely to be in the current release, but that should nevertheless be retained for future consideration.

In parallel to the above classification of reported bugs, we also use a similar scale for prioritizing product features:

1. 1 – Essential – These are features without which the program cannot ship.
2. 2 – Important – These are features which should be in the program.
3. 3 – Desired – These are features that we want to be implemented, if possible.
4. 4 – Extra – These are features that would be nice to incorporate, if there is time.
5. 5 – Wish list – These are features that will probably have to wait for a later version.

Despite the fact that the two classification systems are similar, we generally prioritize bug fixes (levels 1-3) before implementation of new features. The only times in which a bug fix is postponed temporarily are when a feature implementation is incomplete and needs to be finished first, when an upcoming feature will obviate the bug, or when the bug is so minor that delaying the fix has no discernible adverse impact on the product.

As you begin development, it is important that you devise a method for tracking and managing both feature development and bug reports. Throughout the process, priorities invariably change and bugs will be uncovered through testing, and if you do development work for somebody else, new feature requests and change orders need to be handled. A good system will help keep the development in perspective and prevent issues from getting forgotten.

For tracking bugs and features, there are a number of software options, some of which are very expensive. Some ASP members produce reasonable software for tracking product features and bugs, so check the download site for some software designed for that purpose. I personally prefer a simple solution, so my feature and bug tracking is done with WordPad and one physical file folder. Another intriguing approach, which I learned from the member newsgroups, is to use a deck of index cards, one for each issue, and remove items physically when they have been resolved.

[continued in More to come]

[continued from Planning for Quality]

Getting started

As soon as program development commences, you can, and should, begin testing the software in various ways. Once you have adopted the attitude that producing a quality product is paramount, incorporating the testing process into development is the single biggest step that you can take to achieve the desired result.

At this point, it will be very useful to define some terms. The one known to most software users is “bug”, which refers to an unexpected problem with software (as opposed to a design decision or “feature”). The term comes from the early days of electronics, but discovery of the first computer bug is attributed to Grace Hopper, who, in 1945, extracted a moth from a relay that had apparently beaten it to death. She pasted it into a logbook, and now this original bug resides at the Smithsonian Institution, still attached to that same page.

In searching for bugs, there are, essentially, two different kinds of testing, known as “black box” and “glass box” (or “white box”) testing. Black box testing, as the name implies, is testing which treats the software as a black box, checking only the output based on the provided input. Glass box testing, on the other hand, is testing which makes use of special knowledge or access to the inner workings of the software.

Black box testing is the most common form of software testing, and is what most people mean when they use the word, “testing”. One simply runs the software to see if it does what it is supposed to do. If the program does something incorrect or looks wrong, then there is probably a bug, and with some luck, the developer will get a defect report and be able to fix the problem.

Glass box testing methods can significantly decrease the number of software defects and improve software quality. This is especially true in development environments in which glass box testing has not been used previously. There are a number of glass box techniques that can be utilized as development is underway to help identify and eliminate bugs before they reach the black box stage.

Another couple of terms that are commonly used with regard to testing are “internal” and “external”. Internal testing is any form of testing in which the process is conducted and controlled by the developer, without distribution of the product in any form. External testing is any form of testing in which the product is distributed, whether widely or in a limited way, for testing purposes.

[continued in Bug and feature tracking]

[continued from Quality: The Process, Part I]

Planning for Quality

The quality process begins with the initial product concept. From its inception, the development of a product must be planned. Basically, if you do not know where you are going, it is unlikely you will get there. If you do not know the route, you may get lost along the way and probably will not get to your destination efficiently. Neither situation is conducive to quality software.

The tools for helping software development maintain the correct direction throughout a project are design documents. Design documents should do exactly what they say: document the design of a program. The actual contents and approach vary greatly depending on the type of software and the author(s) of the document, but they should provide a written roadmap for the project.

One very important aspect of design documents, and a reason why even lone developers should use them, is that they provide the opportunity to discover flaws in the planning before time is wasted on unproductive activities or projects. When one is forced to document the design, one must think through all aspects of the project. If the project is not viable, for whatever reason, it is better to find out early, rather than too late.

From a quality perspective, the most important aspect of a design document is what is known as the technical specification, which describes in detail the technical aspects of the project, including the program interface and any complex procedures. During the documentation of these items, potential pitfalls can be identified and either corrected by a design change or noted for future consideration.

An interesting approach to interface design specification is to write the interface portion of the help file first, before the programming begins. Again, this forces a developer to consider any issues with the design and usability before time is spent on implementation. Simply, if a procedure is too complex to be easily described in a help file for the end user, then the interface is probably overly complicated to use.

The main goal of design documentation is to determine what the end product should be. This is a “living document”, which means that it should be revisited regularly and, if necessary, changed to reflect any new direction. The design document can help keep the project on track and avoid feature creep or inconsistent functionality. Ultimately, it should be the basis of your software testing plan.

[continued in Getting started]

[This article was originally published in the November 2002 issue of ASPects.]

It can be known as Quality Assurance (QA), Quality Control (QC), ISO9000, or simply “testing”. Regardless of the name used and the particulars of the implementation, it is essential to have a process for making sure that your products exhibit the highest possible degree of quality.

In my previous article, I mentioned the need for testing three times in the same sentence; such is the importance of this topic. The creation of a quality product begins and ends with testing, so it is worthwhile to discuss the different types of testing that can be incorporated into the development process. Although my focus is on development of computer software, much of the process applies to services and other kinds of projects.

The quality process can range from having a fully documented and certified procedure for assuring quality, complete with personnel devoted specifically to maintenance of the process and rigorous testing of the product, down to the lone developer who compiles an executable, runs it once, and then distributes it. It is easy to tend towards the lower end of this scale, through either ignorance or laziness. As independent developers with limited resources, it is probably unrealistic to be at the absolute top of the scale, either. However, we must strive to find a comfort level as close to the top as possible.

When I wrote my first line of code, more than two decades ago, nobody told me about quality, nor even about bugs. The only test was whether the program did what I wanted when the user did what I had anticipated. This changed rather quickly, though, when I got to sit in a computer lab and watch high school students deliberately try to break our games in order to ridicule our capabilities. The challenge became finding ways to make our programs more resilient to these attacks. Though the motivations may be different, today our software is similarly used and abused by our potential customers.

The gauntlet has been thrown down.

[continued in Planning for Quality]

[continued from What Quality is Not]

Keep Looking Up

It is rare that anyone would deliberately ship a shoddy product or knowingly provide a poor service. However, this does happen for a number of reasons. Some of these include limited funding, lack of time, and insufficient talent, which cannot be remedied directly by attitude. On the other hand, sometimes the problem is with perception and awareness, or just a failure to pay attention to detail.

I make the assumption that, as [software developers] who have read this far, you are interested in improving product quality and, therefore, probably already have products that are fairly high on that scale. Nevertheless, we can all improve, and it is important to take the attitude that even the little things make a difference. We need to listen to our users and reviewers closely and resist the natural temptation to dismiss or rationalize criticism. All comments are valid, whether or not they are accurate, and we must pay attention as they tell us where we can yet improve.
Simply by taking the attitude that quality is important and that knowingly providing less than our best for our customers is unacceptable, we can improve both our products and our bottom lines.

Gregg Seelhoff is an independent game developer who serve[d] on the ASP Board of Directors. He can be reached at seelhoff@sophsoft.com.

[end of article]

[continued from Crafting Excellence]

What Quality is Not

In more than two decades in the computer software industry, my experience is that most computer programmers are, in fact, human. For the sake of argument, I will make the logical leap that this also applies to most other jobs within this and other industries. As humans, we are prone to make mistakes occasionally.

Knowing that mistakes are likely to happen, it is important to point out that quality is not the same as perfection, nor should it be. There are too many subjective attributes of even the most basic software to ever achieve perfection, and never shipping any product in the futile search for perfection certainly does not denote quality.

Ironically, mistakes can be opportunities for improving the perception of quality. Most software users are at least sophisticated enough to understand software that does anything worthwhile is bound to have a few bugs. If a publisher or developer is responsive to a bug report from the user, that can potentially instill a greater feeling of comfort, despite the occasional problem. Likewise, involving testers and others in the process helps to create a feeling of proprietorship and, to some degree, loyalty.

Another potential development pitfall that should not be confused with quality is a situation known as “feature creep”. This is the process, basically, in which one begins to think of the omission of a feature as a failure and, hence, continues to add new features and code, seemingly forever. It is tempting to want to incorporate every single feature that any competing product has, but that can be detrimental to the final product. A title with six major features implemented well is more likely to be considered a quality product than one with a dozen poorly implemented features.

[continued in Keep Looking Up]