System Analysis and Design

2nd lecture

Information systems categories Transaction Processing Systems TPS:

Transaction Processing Systems ("TPS") are designed to process routine transactions efficiently and accurately. A business will have several (sometimes many) TPS; for example:

- Billing systems to send invoices to customers- Systems to calculate the weekly and monthly payroll and tax payments

Information systems categories Office Automation Systems OAS:

Office Automation Systems are systems that try to improve the productivity of employees who need to process data and information. Perhaps the best example is the wide range of software systems that exist to improve the productivity of employees working in an office (e.g. Microsoft Office XP, Application SW) or systems that allow employees to work from home.

Information systems categories Management Information Systems MIS:

A management information system ("MIS") is mainly concerned with internal sources of information. MIS usually take data from the transaction processing systems and summaries it into a series of management reports.

MIS reports tend to be used by middle management and operational supervisors.

Information systems categories Decision-Support Systems:

Decision-support systems ("DSS") are specifically designed to help management make decisions in situations where there is uncertainty about the possible outcomes of those decisions. DSS comprise tools and techniques to help gather relevant information and analyze the options and alternatives. DSS often involves use of complex spreadsheet and databases to create "what-if" models.

Information systems categories Executive Support Systems:

An Executive Support System ("ESS") is designed to help senior management make strategic decisions. It gathers, analyses, summarizes and the key internal and external information used in the business.

ESS typically involve lots of data analysis and modeling tools such as "what-if" analysis to help strategic decision-making.

What is Information System Analysis and Design

The complex organizational process whereby computer-based information system are developed and maintained.

عملية معقدة ومنظمة يتم من خاللها انشاء .أنظمة المعلومات وصيانته

The Systems Development Life Cycle

(Life Cycle and Methodologies)What is Systems Analysis and Design development Methodologies and life cycle:

A standard process followed in an organization to conduct all the steps necessary to analyze and maintain information systems.

The Systems Development Life Cycle

Systems Development Life Cycle: -- phases of the life cycle can

sometimes overlap

-- one phase ended and another

began

planning

analysis

design

implementation

testing

maintenance

Developing Information Systems

Systems Analysis and Design Methodologies:

1- unstructured analysis and design(traditional system development life cycle)

2- structured analysis and structured design

3- object-oriented analysis and design

unstructured analysis and design

طريقة قديمة في تحليل النظم بدأت في الستينات مستخدمة المخططات اإلنسيابية

)مخططات بدائية( كوسيلة للتخطيط والتصميم وهي ال تستخدم حاليا اال نادرا نظرا لتعقيد

االنظمة الحديثة

structured analysis and structured design

Ed Yourdon and his colleagues developed structured analysis and structured design in the early 1970s.

They use structured diagram, that why they called structured analysis and structured design.

Making analysis and design more disciplined, similar to engineering field.

The goal was to reduce maintenance time and effort.

Structured analysis and design makes it easier to back to earlier phases in the life cycle when necessary. EX: when requirements are changed.

Tools used: DFDs.

object-oriented analysis and design Systems development methodology based on objects rather than data.

Combines data and processes into single entities called object.

Tools used: Use Case Diagram and Class Diagram.

Different Approaches to Improving Development

Prototyping:

a process of system development in which requirements are converted to a working system that is continually revised through closed work between an analysts and users.

Joint Application Design JAD:

Structured process in which users, managers and analysts work together foe several days

In series of intensive meeting to specify and review systems requirements.

Evaluation

How does MIS differ from ESS?

What is DSS?

What is systems analysis and design?

What are the Systems Analysis and Design Methodologies?