1. G&W Chapter 24: Making Agreements Software Specification Lecture 31
Prepared by
Stephen M. Thebaut, Ph.D.
University of Florida

2. Part V: Greatly Improving the Odds of Success
Ambiguity Metrics
Technical Reviews
Measuring Satisfaction
Test Cases
Studying Existing Products
Making Agreements
Ending

3. Choices, Assumptions, and Impositions
Requirements decisions made directly and consciously are choices.
Those made unconsciously, through bias, error, or lack of information, are assumptions.
Decisions that are thrust upon a project – by law, custom, higher authority, or someone else – are impositions.

4. Important Themes
Assumptions should be elevated to choices or impositions, and then documented.
Consider the “assumption” that elevators will only travel vertically. Is this a choice, an imposition, or perhaps a false assumption?

5. Important Themes (cont’d)
The elevators will travel vertically only because we don’t see any appreciable market for non-vertical elevators at this time. (choice)
The elevators will travel vertically only because none of the states in our marketing area legally allow non-vertical elevators. (imposition)

6. Important Themes (cont'd)
Choices and impositions should be converted to written agreements.
(A signature adds value. Any hint of hesitation should trigger more digging.)
Moving from assumptions to agreements is a risk reducing activity.
In general, all requirements should be made traceable.

7. Sources of False Assumptions
Lack of valid information
Invalidation over time
The “turnpike (or parking lot) effect” (assuming that current load factors will remain invariant with respect to increasing capacity)
Requirements “leakage” – assumptions can be invalidated as new requirements are born.

8. Moving Toward Agreement Process
Write down every assumption.
Trace each assumption to its source: (if not false) promote each to a choice or imposition (if possible – some may need to be deferred until later).
Document the source.
Get participants to sign their names to each written document.
Look for opportunities to agree to actions that will reduce risk.

9. G&W Chapter 24: Making Agreements Software Specification Lecture 31
Prepared by
Stephen M. Thebaut, Ph.D.
University of Florida