Archive of Use Cases Articles

What is the better requirements management model for capturing business rules? The use case, or the UML statechart? In this article, we explore how customer orders are submitted and processed, and contrast how use cases and statecharts expose and document business requirements and business rules.

Should you use use cases or process flow diagrams to document business requirements? At some level, they both document the same thing, they just document it differently. The best requirements will come from doing both - but what if you are forced to choose one? What are the tradeoffs between use cases and process flows? In this article we look at the documentation of failure handling.

You write use cases to define the scope of your project. Use cases describe what people are using your product to accomplish. Use cases provide a framework for defining the details of the product. You can estimate your project effort with use cases. But you have to write the use cases at the right level of detail.

Use case writing is key to effective requirements management. Each use case represents a single idea or logically grouped behaviors. When you define a use case, there are several mistakes you can make. Preventing those mistakes is the first order of business. The second order of business is making sure that the use cases in the system work together. This requires an understanding of the context in which the use case happens. To fully understand a use case you have to know what is promised to be true before the use case happens, as well as what causes the use case to happen. These are subtly different.

We just completed a series of articles detailing how to use Use Case Points for software cost estimation. In this article we have a free MS Excel Spreadsheet for calculating use case points. Download it today to make it easier to do your project cost estimations.

The final step in project cost estimation with use case points is to do the math. First you identify the technical and environmental factors that influence your environment and describe your team. Then you analyze the use cases and actors that describe the expectations of the software and who has them. Finally, you bring it all together to do the math.

Software project cost estimation using use case points takes the approach of estimating the amount of effort based upon what the software is being asked to do - not an analysis of how someone chooses to do it. We’ve looked at technical and environmental factors that influence our estimate. And we’ve done a use case analysis to quantify how much work the software is being asked to do. The last area of analysis focuses on the users of the software.

Software cost estimation with use case points is primarily driven by use case analysis. You take into account environmental and technical factors, but they are ultimately only modifiers of the analysis done on the use cases. Each use case contributes to the project cost estimate, and use cases of varying complexity have a varying influence on the cost estimate.

The environmental factors that describe your development team and environment are the second thing you assess when doing project cost estimation with use case points. Environmental factors primarily focus on the capabilities of your team, but also touch on your process.

The technical factors are the first thing you assess when doing a use case point analysis. Technical factors describe the expectations of the users for the delivered software. Generally, it is an assessment of non-functional requirements. There are 13 technical factors that you have to analyze. Read on to see how.