Exercises

1.	What are the phases of the Systems Development Life Cycle (SDLC) and the purposes of each phase?
2.	What are some examples of the ways you can document your design in the design phase of the SDLC?
3.	What is the difference between a standalone application and a client-server application?
4.	What are the advantages of separating your code into logical tiers in your Access applications?

Answers

1.	The phases of the System Development Life Cycle methodology include requirements gathering, design, development, testing, and implementation. The purpose of the requirements gathering phase is to identify a list of features that the application should include. The design phase takes the requirements and determines how to design an application that meets the requirements. The development phase is where you create the application using forms for the screens and VBA code for the business logic and data access logic. The testing phase allows you to test and fix your application, and should be performed in various phases as the application is developed. The implementation phase is where you roll out the application to end users.
2.	You can use Use Case Diagrams to list the various ways an end user might use the system. You can use Activity or other Flow Diagrams to illustrate the flow of activities in the system. You can use prototype screens to model how the user interface should look. These are just a few of numerous other documenting techniques that can be used.
3.	A standalone application runs entirely on one computer. All of the user interface, business logic, and database elements run on the same computer. A standalone application in Access can be located on a network computer that multiple computers can access, but all computers will be opening the same file. A client-server application is one where the user interface is separated from the database, and the database is located on a server so that it is accessible from multiple computers.
4.	By separating your code into different logical tiers, you can make migrating or improving your application easier in the future. For example, suppose that you include your business logic in one Access module and your data access logic in another Access module. If you need to change your data access code, such as to migrate to another database platform, you can find all code that interacts with the database in the data access layer in one place. This makes it much easier to upgrade different portions of your application without having to weed through the entire application to find the affected portions.