Welcome to the Requirements Writing MOOC. The course is run over five weeks. During the first four weeks you will complete four modules (one each week) that progressively move through the rules for writing requirements. Each week, you will have the opportunity to undertake a module quiz as many times as you wish to ensure that you have a grasp on the module material. The quizzes are drawn from a large set of questions, so each time you do the quiz, you will see new questions to test your knowledge. In Week 5, there will not be any presentations but you will have time to review the four modules and practice the module quizzes again so that you are prepared for the course exam.

As we saw in the last module, the writing of good requirements is essentially about removing the ambiguity from the resulting statement. We first identified a suitable structure for the statement and we then began to look at the rules that we should keep in mind when writing requirements. In this module we continue to move through the rules, particularly as they relate to the use of vague and superfluous words.

In the last module we addressed more of the rules we need to follow in order to develop good requirement statements. In particular we looked at the rules that relate to the use of vague and superfluous words. In this module we address more of those rules, starting with some more rules about other words we should avoid when writing requirements. In particular, we look at avoiding conjunctions unless we introduce a formal convention for logical conditions. We also discuss why we must avoid unbounded statements and escape clauses.

In Module 4, we complete our look at the rules for writing requirements. In particular, we focus on when we should and should not be precise; how to use units, ranges and tolerances; and some final things to avoid (such as cross-references, including pronouns, and the use of “not” in forming negative requirements).