Difference between revisions of "Secrets of understanding requirements"

Latest revision as of 16:01, 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:

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 ==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
+* ''SOMEONE ELSE'' must include a picture or a song in an email
+* Fred must include a picture or a song in a ''NON''-email