PART III

SCENARIOS IN ACTION: CASE STUDIES

OVERVIEW OF PART 3—CASE STUDIES

INTRODUCTION

This part of the book consists of a set of case studies written by authors who have applied scenarios in their work. Each chapter can stand alone as an example of the use of scenarios; but the chapters follow a common framework, explained below, and authors have described some of the lessons learnt from their experience, which we hope will help you to identify approaches for your projects. Therefore, there are several ways of using this part of the book, other than simply reading it from start to end:

• find the chapters that describe the case studies closest to your projects, and study those in detail;
• read the Summaries of all the chapters to get an idea of how scenarios worked out in practice on a range of projects;
• skim through the chapters, especially the Roles Played by Scenarios, Strengths and Weaknesses, and Lessons Learnt sections, to get an appreciation of the relative merits of the various approaches.

STRUCTURE OF THE PART 3 CHAPTERS

Each chapter has the following framework:

Summary

A few paragraphs summarising the case study.

Type of Project

A brief factual statement of the type of project described in the case study.

Applicability

A brief statement of opinion about the types of project that could benefit from the approach that was followed in the case study.

Position in the Life Cycle

A diagram like the one below, showing the parts of the life cycle covered by the described approach.

Roles Played by Scenarios

Explains in a short factual narrative the ways scenarios were used in the project and why. For example, were scenarios used to help to discover requirements? To give designers some context? To guide testing?

Strengths

A description of what worked well on the project because of its use of scenarios.

Weaknesses

A description of what did not work well and the limitations of the chosen approaches.

Case Study

A detailed stepwise account, telling the story of what was done in the project, what happened, what went well, and what went wrong or worked only with difficulty.

Lessons Learnt

A description of the lessons learnt during the project described in the case study.

Keywords

A list of terms for the main concepts used in the chapter.

TOPICS COVERED

The case studies are examples of industrial practice and consultancy from as diverse a set of projects as we were able to find. They vary greatly in scale—though without an example of the very largest projects, where scenario use is uncommon. They illustrate scenarios in the automotive, railway, aviation, telecommunications, and construction industries. We made a special effort to find examples that were not purely about software (to make the point that scenarios are more generally applicable), though it is no surprise that almost all the projects involved a significant element of software development.