What are Requirements?

The simple definition: it's what you need.  

In the software world (Dorfman and Thayer, 1990), requirements are:

• a software capability needed by the user to solve a problem to achieve an objective

• a software capability that must be met or possessed by a system or system component to satisfy a contract, standard, specification, or other formally imposed documentation.

What is a use case?  

A Use Case is one several tools or techniques that we will use to capture or document requirements.  Other tools are such things as workflow diagrams, data models, flowcharts, etc.  The Use Cases will be one part of the complete package of technical documentation that describes our business and system requirements.  In our JAD sessions,  CGI facilitators will be asking lots of questions about how people do various business functions, such as "how does someone transfer an animal from enclosure to enclosure"  to better understand the business process. These discussions will identify how, when, and where a ZIMS user needs to 'interact' with ZIMS.  The results of these discussions will be captured for each specific business function in a detailed Use Case. 

A Use Case describes scenarios in which an “Actor” (Performer, Documenter, Planner etc.) interacts with the “SuD” (System Under Discussion - ZIMS / Organization / Institution). It describes what an “Actor” does and how the “SuD” reacts. A use case describes a complete course of events. Use Cases are a key deliverable of the requirements analysis effort.

Each use case consists of:

• A document describing the use case using terms familiar to the ZIMS User Community.
• An accompanying visual representation of the the interaction between actor and system.

Use cases will be used as a basis for the design of ZIMS, walkthrough's and user acceptance testing.

 There are two types of Use Cases:

 Business Use Case: 

• Describes the interaction between the people, departments and organizations within the ZIMS user community.
• There is no mention of technology since these use cases are focused on business operations.
• The focus of the business use cases is to highlight how the organizations that are part of the ZIMS user community interact – currently and in future.

 System Use Case: 

• Describes the interaction between an “Actor” and a “System” (ZIMS).
• It provides the details of the “Actors” achieving goals within a “System” (ZIMS).