8 Steps for gathering requirements using use casesHeartland IIBA

January 15, 2008

David Kohrell, MCRP, MA, CISA®, PMP®

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Outline

• 8 step use case process• Exercise• Resources – 2 articles

– Fast-tracking acquisition with RUP: Completing a "buy" process during Inception in three steps by David Kohrell (2005)

– Fast tracking the RUP Inception phase: Eight steps for agile use-case generation by David Kohrell (2004)

`http://www-128.ibm.com/developerworks/rational/library/content/RationalEdge/archives/rup.html

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Terms

• Actors • Goals• Use Case• Basic Flow• Alternate Flow• Business Rules• Special Requirements• Pre and Post Conditions

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8 Step Process Overview

• Steps following the sequence of tasks to write a use case – narrative form.

• Some steps may be done concurrently in a group setting – e.g. Step 6 and 7.

• Steps can be used to understand “what is” as well as “what can be.”

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Step 1: Actors and Goals

•Have all actors and their goals been identified?•Which actors can be generalized (combined)?•Which goals are potential use cases?

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Step 2: Develop An Outline Of Use Case(s)

•For goals identify ones that are potential UC.• What are the pieces?

•For each outline level, what are key data?•Outline all use cases.•Prioritize the use case flows.•Decide on final use case list (for initial pass).

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Step 3: Brief Description

What are two to three sentences that describe all actors and basic flow?

Generate content first, worry about wordsmithing later.

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Step 4: Basic Flow

•What event starts the use case?•How does the use case end?•How does the use case repeat?•What is the happy path?•There is one and only one basic flow.

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Step 5: Alternate Flow

•Are there optional situations in the use case?•What may go wrong? What may not happen? •What kind of resources can be blocked?•Which alternate flows are special requirements?

(apply to this use case only) – e.g. non-functional.

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Step 7: Pre and Post Conditions

•What was the previous state?•What happens once the use case is done?

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Step 8: Business Rules

•Review business rules and glossary notes recorded and cataloged.•What items have been noted for the glossary or as global business rules?•Who has the most recent and accurate source document?•Where is it located?

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Exercise15 minutes

1.1. Identify 3 system and/or role Identify 3 system and/or role actors for the Heartland IIBA. actors for the Heartland IIBA. Also identify the goals of each Also identify the goals of each actor. 4 MINUTESactor. 4 MINUTES

2.2. Determine which actors and Determine which actors and goals you’ll pursue – which goals you’ll pursue – which ones involve automation. 5 ones involve automation. 5 MINUTESMINUTES

3.3. Write a use case for one actor Write a use case for one actor and goal – or at least the and goal – or at least the description and basic flow 6 description and basic flow 6 MINUTESMINUTES

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Wrap Up

• Additional support &a copy of this slide deck are available at www.tapuniversity.com (just click on resources)

• Join us Feb 21-22 for a 2 day Requirements Elicitation Workshop (Westside Community Conference Center) or May 12-15 for a CBAP preparation class (Mahoney State Park). TAP is becoming a IIBA endorsed education provider