Sunday, March 27, 2011

Tutorial 3: System development cycle

There are five steps in the system development cycle which include planning, analysis, design, implementation and operation support and security.
                                           Planning 
The first phase of the system development cycle is planning. In this step, you figure out the details such as when you can schedule work, whose on the team, and the requirements you need to meet. A major step is defining the problem. You must first understand why you need systems in order to be sufficient. You will get many project requests so it is also important to review and approve or disapprove them. You must prioritize and decide which projects are most sufficient and important. If you disapprove a project, you have to explain  why one project is approved ahead of another persons project. Sometimes economic reasons and sometimes one project will be more sufficient.
In this step you also need to allocate resources and from a development team.



                                                                     Analysis
In the second phase of system development, analysis, you must create a plan. Also, you must first conduct a  feasibility study. Make sure there isn't already technology to help you create this. Look more at requirements, how to set them up, how the data moves in and out and other ins and outs of the project. An important factor is that it is compatible with the current environment (users will be able to use it).
If you don't have the resources needed you might need to buy additional licenses and hardware.

A good think to do is look at all the different requirements by interviews and surveys given and then recommend a solution.
The Logical design is what it will do not how it's going to do it.
During the analysis phase
Avoid missing the big picture, like the goals of the system.

There are also two different Approaches for the modeling.
Process modeling: getting from input to output
object modeling: combines data and processes and predefined objects


Process Modeling
Entity Relationship Diagram Entity: Any object that has data

Data Flow: how the data moves throughout the system. For example: smartdraw 7.0


Object modeling: data and processes combined to make an "object" case diagram shows user interaction with system. Make it possible for students to turn in and teachers to look up evaluation. Important that it is easy to understand.


Design
First step of the design phase is to create technical plan, which includes figuring out how to implement all requirement.
Also in this phase, you should complete the final review and sign-off on the design.

Deliverables
Detailed specification with approval from clients
The most important part of this phase is the actual physical design.
Physical design: new and existing data and security.

During this phase, you need to decide if you have to buy additional hardware and software to complete the project.
Involves 4 critical steps:
Technical specifications: Research to determine needs
Request proposals: from vendors
Evaluate and test: check references lowest price isn't everything
Deliverable: include timeline and make appropriate recommendation with rationale
Quality review: all clients need to sign off on design


Implementation
Do programming testing and create documentation
Four major activities:
1. Develop programs and documentation
2. Install and test "blind testing" tested by people who are not involved ppl whoa re involved might miss
3. Train top ten reason for system failure
4. Convert from old system to new system with lowest disruption as possible

Four conversion strategies:
1. parallel: same time
2. pilot: smaller user based
3. phased: modular
4. direct: just do it



Operation support and security
The review of program is usually done 3-6 months after released by users and developers. It deals with ongoing issues such as maintenance performance and security. Add new functionality, or replace something if it insufficient

security: see what kind of risks are exposed, and making sure everything is safe for users.

Those are the five steps in the system development cycle. Hopefully after reading this tutorial you have a better understanding of each of the steps and there significance in the cycle.

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