Team Skill 6 - Building The Right System Part 2: Traceability, Change and Quality Sriram Mohan

Outline Tracing Requirements Managing Requirements Assessing Requirements Quality

Tracing Requirements

Traceability: Primary Questions Why is tracing important? What mechanisms are used for tracing? Why we care – remember this triangle?

Traceability: The Problem How do you know, if you’re at one of these later stages, that you have a requirements fault?

In general, how to trace… Use Traceability matrices

With use cases, for instance…

Managing Requirements

Managing Change: Primary Questions How do you capture change requests? How do you respond to these (individually & overall)? How does this tie-in with tracing requirements?

A Process for Managing Change – 1/3 Step 1: Recognize that change is inevitable, and plan for it

A Process for Managing Change – 2/3 Step 2: Baseline the requirements This means they are signed-off on, and From then on, they fall under change control – see below Step 3: Establish a single channel to control change No ad hoc additions No ad hoc fixes, either

A Process for Managing Change – 3/3 In  this big picture, you especially need to know what “release management”  is! Step 4: Use a Change Control System to Capture Changes Step 5: Manage Change Hierarchically Figure on middle right from http://www.debian.org/vote/2002/platforms/raphael

Follow the link There is a dependency between the various artifacts involved in requirements mgmt Follow the chain and make sure that the change is propagated

Assessing Requirements Quality

Quality Issues Products vs. Processes Review Methods Checklists

Products vs. Processes Organizations that produce high-quality products invest in high-quality processes. Product quality can be measured through testing. How can we measure process quality?

Review Methods Informal Formal Active Ask a peer to read and give comments Formal Ask a peer to prepare for review Record and report results of review Active Interrogate reviewer

Checklists Look for anticipated defects Some defects apply to almost all artifacts Does the artifact exist? Some defects are artifact-specific Have you identified all stakeholders?

Problem Statement Checklist Has a problem statement been drafted? Is it written in an easy-to-understand way? Does the team understand it? Has it been circulated for agreement to the key stakeholders, including management? Do the team members have agreement that this is the problem they are trying to solve?

Supplementary Specification Checklist (1/2) Have you established an appropriate template? Are all non-functional requirements included in the supplementary specification? Have requirements for usability, reliability, performance and supportability been captured?

Supplementary Specification Checklist (2/2) Have design constraints been identified? Have supplementary requirements been linked to use cases where appropriate?