- A system is a set of interrelated elements (part, processes, components, functions) which operate together to achieve some objectives and common goals. Any system consist of:-
- Input system design
- Output system design
- Processing system design
Input system design
Every system requires some form of input data. Where data consists of basic facts that are the
System’s raw material. There are several things must take in consideration:
- Define the input requirements
- Selecting input media
- Classify the data & design coding system
- Design the shape of input data
Output system design
The system process input data and produce information of a useful form of output. Where
Information is a data that has been changed into a useful form of output. In output system
Consideration:
- Define the output requirements
- Selecting output media
- Design the shape of output report specification
- Define the content of output reporting
Processing System Design
To have an accurate processing and get the desired result, the data must coded, this coding is essential in data processing for several reasons:
- Precise identification
- Storage spaces
- Data entry effort
- Fast access to stored data
- Flexibility
- Security
To achieve good coding the facilities bellow must gain:
- Unique
- Meaningful
- Process able
- Brief
- Sort able
- Expandable
Feedback
It is a mechanism takes some of system output and feeded back to the input system in order to control the system behavior to make its works can be done within control limits. To put the data under any request and not lost it a file mechanism must exist, this facility need to:
- Define and identify the file media
- Define and identify the organization and access methods
- Select the processing type
- File efficiency, no. of data processing when using the file at one time
- File size (capacity)
Analysis Process
1- Is the examination, identification, evaluation of components and interrelationship involved in the sys. From problem through maintenance and modification phases.
2- Is the study of problem prior to take any action.
Analysis Steps:
Sys. Analysis depends on:
a. Sys and its environment.
b. Analyst experience and skills.
c. Collected facts.
So there are no standard rules for analysis for all cases but, there are general steps can followed:
- Examine the collect d facts, and be sure these facts comprehensive (completeness) and correct.
- Classified these facts into their elements.
- Establish logical relationships between these elements.
- Suggest the proposed alternatives solutions to the current sys. and evaluate them.
- Choose the suitable alternative and identify its requirements.
Disadvantages of missing (ignoring) the analysis steps:
- Difficult to design the sys and may reach the case (over design) which lead to a high cost.
- The analyst may fail to discover the problem.
- = = = = = develop positive ideas.
- = = = = = identify the requirements of the new sys.
- = = = = = to evaluate and study the alternatives.
The successful analysis process should involve the following:
1- Select an optimal target.
2- Producing detailed documentation of the target in such a manner that subsequence implementation can be evaluated to see waether or not the target has been attained.
3- Producing accurate predications of the important parameters associated with the target including: cost, benefits, schedules and performance characteristics.
4- Obtaining concurrence on each of the items above from each of the affected parties
In analysis phase the sys analyst should begin by identifying the problem and other articles as follows:
1- Determine who the user are.
2- Determine how to gather information.
3- Collect and analyze the information.
4- State the problem.
5- Describe the current sys.
6- Quantify the cost associated.
7- Summarize the current sys. limitations and constraints.
8- Establish all preliminary objectives and requirements.
9- Formulate general alternatives solutions.
10- Do preliminary cost/benefit analysis for each solution.
11- Estimate time and cost involved to develop each alternatives detailed solutions.
12- Summarize finding and state weather the problem warrants further development analysis.
The Preliminary Study Phase
Preliminary study phase contain on:
- Problem definition.
- Objectives setting.
- Feasibility study.
- Plan.
· Problem definition.
v Structure organization as a function, as a management levels charts.
v Management ratio through years:
§ Stock ratio
§ Profile =
§ Sales =
§ Product =
v Historical background.
§ Policies
§ Decision type
§ Decision limiting
§ Decision reasons
v Staff opinions.
· Objectives setting
v Clearly defined
v Quantified
v Time constrained
v Obtainable objectives
· Feasibility study
v Economic conclude cost/benefits
v Technical conclude the H.W and people
Well done feasibility study enables the:-
1. Lack of top management support.
2. Failure to clearly specify problem objectives.
3. Over optimization.
4. Estimations errors.
5. Crash project.
6. The H.W approach.
The S ystem Analyst Position
A systems analyst investigate, analyze, design, and maintains a company’s information systems to performs those tasks, a system analyst constantly interacts with users and managers within and outside the organization.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .