Tuesday, November 11, 2014

System Analysis and Design

System Analysis

A system analysis team is often brought in to review an existing system and suggest a number of improvements. The existing method used may be either a manual paper-based system or a computer-based operation that is no longer regarded as adequate for the task.
The systems that we are talking about are the systems within organizations and businesses - systems of communication, financial systems, manufacturing systems, etc. - basically the systems that make the organization or business work.

Example of System Analysis:

Paper Based System


            Paper based system is a manual system that some companies still use nowadays. Even though there is a computer, some still take advantage of paper system rather than trusting the computers.

Advantages:
  •         Easy to use
  •          Cost saving
  •          They do not crash like computers do


Disadvantages:
  •         Limited by physical storage space available
  •          Very difficult to analyze the data
  •          Records can be lost or misfiled

 

Computer Based System


            Computer based system is an information system that is based on computer hardware and software technology for processing and disseminating information.

Advantages:
  •          Can hold a vast amount of data
  •          The database can be kept secure by use of passwords
  •          Records are stored safely


Disadvantages:
  •          Computers may crash
  •          Depends on electricity
  •      More expensive than paper-based system because it requires electricity

Analysis Stage


                Analysis stage is the stage where current system is looked in detail in order to figure out what changes need to be made to improve the system. Below are the steps:

  •          Collecting data from the current system
  •          Identifying the description of the current system
  •          Figuring out the problems with the current system
  •          Solving the problems
  •          Identify the requirements of the new system
  •          Producing a cost-benefit analysis
  •          Producing a data flow diagram


There are four methods in order to find the facts:

Questionnaires

     Questionnaires are research instrument consisting of a series of questions for users to complete.

Advantages:
  •          Practical
  •          Large amount of information can be gathered
  •          Results can be checked quickly

Disadvantages:
  •          Lacks validity
  •          Nobody knows whether the respondent is honest while filling in the questionnaire
  •          Different questions interpretation

 

Observation


                Observation is the process of observing something or someone carefully or in order to gain information.

Advantages:
  •          Not expensive
  •          A very direct method
  •          Problem of depending on respondents is decreased


Disadvantages:
  •          Problems of the past cannot be studied
  •          Attitudes cannot be studied
  •          More time is wasted


Interviews


            An interview is a conversation between two or more people where questions are asked by the interviewer to elicit facts or statements from the interviewee.

Advantages:
  •          Time and cost saving
  •         Sufficient information collected
  •          Depth analysis occurs


Disadvantages:
  •          Lack of attention
  •          No record/evidence
  •          Interviewer’s biases


Looking At Existing Paper Works


            The existing paper works include the information needed to improve to a better new system. Data are recorded to be analyzed to do the improvements needed.

Advantage:
  •          Complete record of data about the current system


Disadvantages:
  •          Time consuming
  •          Very expensive

 

Design Stage


Design is the second stage after the analysis stage is clear. It doesn’t matter what type of design is created. What is important is a clear design. Below are the steps:

  •          Designing data entry forms/input forms
  •          Designing screen layouts
  •          Designing printed outputs/reports
  •          Producing system flowcharts
  •         Designing data validation methods
  •          Designing structures to store data
  •          Selecting and designing hardware and software requirements
  •          Designing data verification methods
  •          Designing a testing strategy/plan


More depth two of these tasks are:

Verification


            Verification is the act of reviewing, inspecting or testing, in order to establish and document that a product, service or system meets regulatory or technical standards.

Two common ways of verification checks:

  •          Double Entry

In this method, data is entered twice, using two different people. The computer compares the two entries, either after data entry or during the data entry process, and identifies any differences.
  •         Visual Check

Checking for errors by comparing entered data on the screen with the data in the original document


Validation 


            Validation is to check the accuracy of the system. It is also to check to see if it satisfies certain criteria when input into a computer.

Types of Validation Checks:









References:








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