Difference between revisions of "Secrets of understanding requirements"

Revision as of 15:59, 22 April 2020

When requirements are hard to descern, you can get a better understanding by playing with words. Let's take a rather simple looking requirement:

Now, we can apply inverses at different points to change meanings. This allows us to ask questions:

@@ Line 3: / Line 3: @@
 ==Word tricks==
-When requirements are hard to descern, you can get a better understanding by playing with words. Specifically, you need to be able to simply define each noun and each verb you use. But that's easier said than done.
+===Negation and inversion===
-* Fred needs to include a picture or a song in an email
+When requirements are hard to descern, you can get a better understanding by playing with words. Let's take a rather simple looking requirement:
-Pronouns: Fred
+* Fred must include a picture or a song in an email
-Verbs: Needs, Include
-Nouns: Picture, Song, Email
-We can see that Fred is a human, a user, perhaps a particular type of user. Let's refer to him a USER.
+Now, we can apply inverses at different points to change meanings. This allows us to ask questions:
-Our first verb, "need", is actually rather special: It means MUST, rather than WANT, SHOULD, or COULD. But further clarification is required, and we can learn a few things using '''negation''':
+* Fred MUST NOT include a picture or a song in an email
+* Fred must include a picture AND a song in an email
-* Fred DOES NOT need to include a picture or a song in an email
+* Fred must include a picture or a NON-song in an email
+* Fred must include a NON-picture or a song in an email
+* Fred must EXCLUDE a picture or a song in an email