The design phase involves describing the desired features and operations of the system including screen layouts, business rules, process diagrams, pseudo code, and other documentation. The two primary activities involved in the design phase are:
1. Design the IT infrastructure.
2. Design system models.
1. Design the IT Infrastructure
The system must be supported by a solid IT infrastructure or chances are the system will crash, malfunction, or not perform as expected. The IT infrastructure must meet the organization’s needs in terms of time, cost, technical feasibility, and flexibility. Most systems run on a computer network with each employee having a client and the application running on a server. During this phase, the IT specialists recommend what types of clients and servers to buy including memory and storage requirements, along with software recommendations. An organization typically explores several different IT infrastructures that must meet current as well as future system needs. For example, databases must be large enough to hold the current volume of customers plus all new customers that the organization expects to gain over the next several years.
2. Design System Models
Modeling is the activity of drawing a graphical representation of a design. An organization should model everything it builds including reports, programs, and databases. Many different types of modeling activities are performed during the design phase including:
● Graphical user interface (GUI) is the interface to an information system.GUI screen design is the ability to model the information system screens for an entire system using icons, buttons, menus, and submenus.
● Data models represent a formal way to express data relationships to a database management system (DBMS).
● Entity relationship diagram (ERD) is a technique for documenting the relationships between entities in a database environment.
