SOFTWARE DESIGN

STEP BY STEP PROCESS OF SOFTWARE DESIGNING

Software design: 

Software design is a process to transform user requirements into some suitable form, which helps the programmer in software coding and implementation. Once the requirements of a software system have been established, we proceed to design that system. Software design consists on the following stages

Problem understanding: 

Look at the problem from different angles to discover the design requirements.

Identify one or more solutions: 

Evaluate possible solutions and choose the most appropriate depending on the designer's experience and available resources.

Describe solution notions: 

Use graphical, formal or other descriptive notations to describe the components of the design.

1). Architectural design: it is an early stage of the system design process represents the link between specification and design processes, often carried out in parallel with some specification activities. It involves identifying major system components and their communications

Architecture and system characteristics:

Performance:

Localize critical operations and minimize communications. Use large rather than fine-grain components

Security:

Use a layered architecture with critical assets in the inner layers.

Safety:

Localize safety-critical features in a small number of sub-systems.

Availability:

Include redundant components and mechanisms for fault tolerance.

Maintainability:

                  Use fine-grain, replaceable components