System analysis and Design

 

In this blog, I am going to show you about the system analysis and design. Here are the steps.

 

Analysis

It is a stage when the company or you check existing systems to see what they lack and what you can improve in your own system.

1.     You collect the data of the other/current systems

2.     See how the existing system works (e.g. their Input, Processing and output/result)

3.     Finding the Problems of the existing system

4.     Agreeing with the customer about the Target of the system

5.     Finding and agreeing with the customer about their requirement/Need

6.     Understanding about the customer’s needs

7.     Analysis about the cost of the system and the profit

8.     Modeling its process aspects

On the first step, which is collecting data, there are 4 ways you could do it: Observation is observing a person using the other/current system

Questionnaires are sending questionnaires to the customer to see their view on the existing system

Interviewing is a session to interview the customer/employee

Looking at existing paperwork is seeing the paper files that tell you how the system works. (Ex. manuals/instruction)

Design

This is the stage where you design and make your own system or the stage to improve your own system after the last stage, Evaluation and review, is done.

At this Stage, you design what it will look like (Ex. Screen layout, input and output form, file structure, etc.), what the system requirement is (Software and Hardware), selecting & designing rules and how the system works.

 Verification

A way to prevent errors when data is copied to another location/medium. There are 2 common ways, which are:

Double Entry : the data is entered twice. Then the computer compares the two data, whether during or after the data entry, if there are any differences between the two.

Visual Entry : It Checks the data for errors by comparing  the data on the screen with the original Documents

Validation

A process to see if the data meets the criteria when it is inserted to the computer. Here are some common techniques of validation when writing computer software:

Range Check = Check if data is within acceptable requirements

Length Check = Check the input data has the required numbers of Character

Character Check = Check if it has no invalid characters

Format Check = Check if the data is in a specific Type/Format

Limit Check = Check to see the Limit or how far can it work

Presence Check = Check if the data is there and not missed

Consistency Check = Check to see if each field is tied up/ responding to each other

Check Digit = Check if there is a mistake in the data in digits