Week 8 of SAD

The Nature of Good Design

At this stage we've completed analysis, done our System Analysis Report or System Requirements Specification..

As stated in the textbook, the objective of the design phase is “to define,
organize, and structure the components of the final solution system that
will serve as the blueprint for construction.” (p. 318)

I think this phrase summarises the whole design phase. What more can i say? just kidding, here's my quick summary....

• There are many people involved in making a good design. Many spceciallists such as software devlopers, senior programmers, graphic designers, even HCI (Human Computer Interaction) specialists.
• The deliverable is the Design Report (assignment two).
• Design can be approached in many ways, the study guide focuses on two
• structured, using the waterfall approach to the SDLC
  
• object orientated (OO), taking an incremental
• Broad and detail design can be approached by top-down or direct entry. the text recommends top-down is the best.
• Key design activities (from Study guide, and SJB)

• Design and integrate the network
• Design the application architecture
• Design the user interfaces
• Design the system interfaces
• Design and integrate the database
• Prototype for design details
• Design and integrate the system controls

• Components of Design (these are much the same as the design activities):
  
• network
  
• architecture,
  
• user interfaces,
  
• system interfaces,
• database, and
  
• security controls.
• (also design of manual procedures, which is vital when considering the users and the actual operation of the system as users and trainers )
• a crutial step is integrating with the existing systems
• Coordinating information during design - there are many people working on different aspects of designing a new system, however these components are not used seperately, so it is essential for communication between them to be thorough, which can be done using software tools for collaboration such as Lotus Notes, or Wikis
  
• Another typo in the study guide, SG8, 4.4, Coordinating information during design: "For these reason, it is..." surely should be "for these reasons".
• During analysis, we determine the requirements of the application deployment environment, in design, we add more detail and expand on this.
  
• deployment environment refers to the range of hardware, software and networking utilised to enable the system to operate.
• The deployment environment is determined by the needs of the system and it its users.
• Application Architecture - most systems today interact with other systems
  
• Three Layer Architecture
• The view layer - e.g. mobile or computer access
  
• The data layer - e.g. oracle or mySQL for the database
  
• The business layer
• Networks: how are they to be implemented?
• Database design
• Designing for change is necesarry as not all systems are ideal especially over time. The system needs to have opportunities in place to be updated or modified.

I like how the summary in the study guide is one paragraph of text... there are definately different types of summaries, ones that cover everything a bit, or ones that just mention the broad areas that you've covered. This wasn't a quick summary, it took a long time.


(n.b. this blog was created useing the XB (extreme blogging) method... possibly not as useful as in a programming situation, however it helped with a few spelling errors.)