System Design Introduction

Introduction :

• The design activity begins when the requirements document for the software to be developed.
• Design focuses on module view.
• The design of a system is essentially a blueprint or a plan for a solution for the system.
• The design process for software systems often has two levels.

1. At the first level the focus is on deciding which modules are needed for the system, and how the modules should be interconnected. This is what is called the system design or top-level design.
2. In the second level, the internal design of the modules, or how the specifications of the module can be satisfied, is decided. This design level is often called detailed design or logic design.

• A design methodology is a systematic approach to creating a design by applying of a set of techniques and guidelines.
• A design should clearly be verifiable, complete (implements all the specifications) traceable, and Simple.
• The two most important concern of designers

1. Efficiency of any system is concerned with the proper use of scarce resources by the system.
2. An efficient system is one that consumes less processor time and requires less memory.