A Guide to Write Effective Use Cases

Introduction

Use Cases portray how an actor will interact with a system to give an output which is of importance to the user or the stakeholders. Actors are the users who will interact with the user interface. Use case specifies a list of actions or steps between an actor and the system. Thus, use cases are dynamic models which describe how the state of various objects changes when events occur. Use cases are not design specifications. They are user requirements which can be portrayed in a diagrammatic form, text form, flow/sequence charts or programming languages; which describe the functionality of the system that provide value. They are effective means of communicating detailed information to meet the project development goals and help in achieving business goals.

Use Case Diagrams

Use case diagrams are a type of Unified Modelling Language diagrams, defined by Object Management Group, through which one can analyse the use cases. They provide realistic overview or visual reference of the components of use cases. These diagrams can be made depending upon the relationship between the actors and the system. They help in identifying needs of the user.

Effective Ways for Writing Use Cases

The definition of a use case sounds simple, but when it comes to depicting them, it takes a lot more than just a clear understanding of the definition. There are various factors involved which need to be taken into consideration for writing or presenting an effective use case.

• Firstly understanding what a use case is (and is not), different terminologies involved while making use cases, important elements of use cases, information required for making the flow, kind of flows involved, etc.
• It is important to concentrate on the result of a use case and not just its functionality. Without an effective result, a use case holds no value. 
• They should be UAT based. 
• Use cases should be like the pieces of puzzle, which fit together to create a story. They should be structured well, to form a clear picture of the scenario. 
• It becomes easier to portray the whole picture by breaking down the process and modularize it. But again, one should be able to tell the entire concept to illustrate end-to-end framework. References help to achieve this goal. Never use references in the main flow as it can divert the focus from the main flow to another flow, which is not advised. 
• Create a single main flow for a particular use case. Don’t try getting into making multiple for the same process. This will defy the purpose of the use case and create confusion in what goal needs to be achieved. The main flow should capture details when things go right and target is accomplished. 
• One can create alternative flows. They explain the process when there is a deviation from the normal path. These variances can be errors or exceptions. However, these deviations are not comparatively important to the main flow. 
• Try putting yourself in the actor’s shoes and analyse the situation. Write or represent the use case based on this analysis so that it makes the system user-friendly. 
• Write a use case in a way which leaves no ambiguity while narrowing down at the goal to be accomplished and understanding the system from user-perspective. One can achieve this by putting into practice the above ideas and doing more research work to better oneself. 

Conclusion

A well written use case with a steady approach becomes a way to achieve business goals. Users, stakeholders as well the development team should unanimously agree and understand the approach chosen. It not only makes the development part easier, but also lends the system a quality in terms of obstacle free operation along with the simplicity of system. Also, an organization can come up with a standardized way of documenting the guidelines for making use cases.

About Author:

Devika Vaghela  is a consultant in Systems Plus Pvt. Ltd. Within Systems Plus, she actively contributes to the areas of Technology and Information Security. She can be contacted at: 

devika.vaghela@spluspl.com