Articles for 'Karl Wiegers'

How often has a customer asked you to write software that is user-friendly, robust, fast, or secure? No one will argue that those are worthy goals that everyone wants in their software products. However, they are terrible requirements. They give you no idea of just what “user-friendly” means, or how to tell if you’ve achieved the desired characteristics that mean “user-friendly” to a particular customer.

No matter how thorough a job you do on requirements elicitation, there is no way to be certain that you have found them all. No little green light comes on to announce “You’re done!” You should always plan on new requirements trickling in throughout the project. However, an excessive rate of change of requirements suggests that important requirements were overlooked during elicitation.

In an ideal world, a single, full-time, expert user would indeed be sitting within view—“on sight”—of developers, ready at a moment’s notice to speak definitively for the entire user community. In reality, this is unlikely in most situations.

The CEO of a major corporation who was present when I described requirements traceability at a seminar asked, “Why wouldn’t you create a requirements traceability matrix for your strategic business systems?” That’s an excellent question. He clearly saw the value of having that kind of data available to the organization for each of its applications. If you agree with this executive's viewpoint, you might be wondering how to incorporate requirements traceability into your systems development activities in an effective and efficient way.

The most common way to represent the links between requirements and other system elements is in a requirements traceability matrix, also called a requirements trace matrix or a traceability table. When I’ve set up such matrices in the past, I made a copy of the baselined SRS and deleted everything except the labels for the functional requirements.

Simple requirements changes often have far-reaching impacts, necessitating that many parts of the product be modified. It’s hard to find all the system components that might be affected by a requirement modification. Assessing the impact of a proposed change is easier if you have a road map that shows where each requirement or business rule was implemented in the software.

Many BAs wait until their requirements specification is complete before they present it to some reviewers. Busy developers, testers, project managers, and users have difficulty finding the time to scrutinize a large document on short notice. It’s far more effective to review an evolving document incrementally. Give reviewers just a few pages at a time, preferably soon after an elicitation activity.

In my view, the most powerful quality practice available to the software industry today is inspection of requirements documentation. A peer review is an activity in which someone other than the author of a work product examines that product to find defects and improvement opportunities.

There is no single correct way to document specific requirements information. Every BA needs a rich tool kit of techniques at her disposal so that she can choose the most effective requirements view in each situation. In this article I offer some ideas about how to make that choice.

An effective business analyst doesn’t just “write requirements.” Instead, the BA should think about the most appropriate way to represent requirements-related information in a given situation. Besides the traditional default of writing natural language statements, the BA should determine when a picture or some other representation would be valuable.

There are three basic checkpoints the business analyst can facilitate to help ensure that he or she is on the right track. Two are informal, merely a get-together with other parties to review the situation and not fraught with the imprimatur of approval. The other is a more formal presentation. I’ll address each of the three checkpoints in this series.

If you create only one view of the requirements, you must believe it. You have no other choice. If you develop multiple views, though, you can compare them to look for disconnects that reveal errors and different interpretations. There’s an old saying, variously attributed to the Swedish Army, the Swiss Army, the Norwegian Boy Scouts, a Scottish prayer, and a Scandinavian proverb: “When the map and the terrain disagree, believe the terrain.”

There’s an old fable about six blind men who encountered an elephant for the first time. Although they couldn’t see it, they wanted to learn what an elephant was like. Each of them touched a different part of the elephant.

There are several situations in which recording only high-level requirements information increases the project’s risk. When you encounter situations such as the ones described in this article, expect to spend more time than average developing detailed requirements specifications.

Several conditions make it appropriate to leave the requirements descriptions at a higher level of abstraction. Recognize that these are broad guidelines. The BA should perform a risk-benefit analysis to balance the potential downside of omitting important information against the effort required to include it.