Object design - Design versus construction
What should be asked about the design of a system?
Technology changes extremely fast. What questions should be asked about the design of a system before proceeding with the construction of that system?
Jumping to programming solutions without specifying the goal of the implementation would be like telling some builders,
Quick, build me a door.
The construction workers should refuse the construction and start asking questions like,
- What kind of door?
- Do you want it to open to the left or right?
- Is it to be an inside door or an outside door?
- Main entrance, back door, closet, security door, screen door, etc.
- What dimensions? What composition?
These questions are all about design.
There are an almost infinite number of technological solutions to any problem.
The question is what criteria will you use to base your choice of the most appropriate solution?
Transition from requirements to design
The purpose of the analysis phase is to figure out what the business needs. The purpose of the design phase is to decide how to build it. System design is the determination
of the overall system architecture consisting of a set of physical processing components, hardware, software, people, and the communication
among them that will satisfy the system's essential requirements.
During the initial part of design, the project team converts the business
requirements for the system into system requirements that describe the technical details for building the system. Unlike business requirements, which are listed
in the requirements definition and communicated through use cases and logical process and data models, system requirements are communicated through a collection of design documents and physical process and data models.
Together, the design documents and physical models make up the blueprint for the new system.