1. System Analysis and Design
- Mr. Ahmad Al-Ghoul
Hi students how are doing today
This is the first sequence in the second chapter of system analysis and design course, before looking to the subjects that we will discuss in this sequence lets have an overview of this chapter
This chapter describes characteristics of system development methodologies, why it used, how to select a methodology, and the popular methodologies
The chapter describes many analytical skills a systems analyst needs and discuss the technical, management, and interpersonal skills
The chapter Describe systems analysis phase activities and the end product of the systems analysis phase
The chapter then discusses system requirements and fact-finding techniques, which include interviewing, documentation review, observation, surveys and questionnaires, sampling, and research
The chapter will learn you how to use data and process modeling techniques to develop a logical model of the proposed system and document the system requirements.
The chapter will learn you how to use object-oriented methods to document, analyze, and model an information system using (UML)
The last topic describes the remaining activities in the systems analysis phase, which include evaluation of alternative solutions for hardware and software, preparation of the system requirements document, and presentation of the system requirements document to management.
Now lets look to the topic that we will discuss in this sequence, we will discuss, Systems Development Methodologies
We discussed this topic briefly in the first chapter but we will discuss in more detail in this sequence and the coming two

2. System Analysis and Design System Analysis
learning Objectives
Explain the Characteristics of a Good Analysis Method
Explain Why Use a Methodology
Describe the three categorizes of system development methodologies
Process-centered Methodologies
Data-centered Methodologies
Object-oriented methodologies
Explain Waterfall Development, Parallel Development, rapid application development (RAD)
Avicenna
System Analysis and Design System Analysis

3. System Analysis and Design System Analysis
Introduction
The process of system analysis and its planning includes various stages.
Over the years various methodologies have been defined for this process.
The methodologies themselves constitute a method that regulates the various stages in the process of
planning and developing the information system.
Each methodology has its own advantages and disadvantages but, generally, the correct methodology must be adapted to the required system.
Avicenna
System Analysis and Design System Analysis

4. System Analysis and Design System Analysis
Introduction
A methodology is a formalized approach to implementing the SDLC.
Justified by experience
A methodology may or may not prescribe a Life Cycle Model.
The methodology will vary depending on whether the emphasis is on businesses processes or on the data that supports the business.
Avicenna
System Analysis and Design System Analysis

5. Systems Development Methodologies
Characteristics of a Good Analysis Method
Graphical with supporting text.
Allow system to be viewed in a top-down and partitioned fashion.
Minimum redundancies.
Reader should be able to predict system behavior.
Easy to understand by user.
Avicenna
System Analysis and Design System Analysis

6. Systems Development Methodologies
Why Use a Methodology?
Distilled experience/best practice
Ensures user involvement
Helps inexperienced analysts
Provides planning and control
Avicenna
System Analysis and Design System Analysis

7. Systems Development Methodologies
Process-centered Methodologies
This kind of methodologies focus on defining the activities associated with the system.
concentrate on representing the system concept as a set of processes with information flowing into and out of the processes.
Avicenna
System Analysis and Design System Analysis

8. Systems Development Methodologies
Data-centered Methodologies
These methodologies focuses on defining the content of the data storage containers and how they are organized rather than the activities which comes later.
Data-centered methodologies utilize data models as the core of understanding the system concept, other models will be less important.
Avicenna
System Analysis and Design System Analysis

9. Systems Development Methodologies
Object-oriented methodologies
This methodology attempts to balance the focus between processes and data.
Object-oriented methodology work well in situation in which complicated IS need continues maintenance, adaptation and redesign
Avicenna
System Analysis and Design System Analysis

10. Systems Development Methodologies
Waterfall Development
With waterfall development- based methodologies, the analysts and users proceed sequentially from one phase to the next.
The advantages of waterfall development-based methodologies are:
The system requirements are identified long before programming begins.
Changes to the requirements are minimized as the project proceeds.
Good for project management
Results in solid, well-constructed systems
Avicenna
System Analysis and Design System Analysis

11. Systems Development Methodologies
The disadvantages of waterfall development-based methodologies are:
The design must be completely specified before programming begins.
A long time elapses between the completion of the system proposal in the analysis phase and the delivery of the system.
Difficult (expensive) to accommodate change after process is underway
Avicenna
System Analysis and Design System Analysis

12. Systems Development Methodologies [3]
Waterfall Development
The Waterfall model is the basis of most of the structured development methods that came into use from the 1970s onwards. It provides a framework for planning top – down systems development. The development flows down a number of successive stages are typically:
System planning
Systems analysis;
Systems design;
Systems implementation
Avicenna
System Analysis and Design System Analysis

13. Systems Development Methodologies
Parallel Development
This methodology attempts to address the long time interval between the analysis phase and the delivery of the system.
Avicenna
System Analysis and Design System Analysis

14. Systems Development Methodologies [3]
from the figure you can see that the parallel methodology begin by first planning the system then analyze the whole system after that A general design for the entire system is performed and then the project is divided into a series of distinct subprojects. Each sub project has its design and implementation phase after that you can implement the whole system together
Avicenna
System Analysis and Design System Analysis

15. Systems Development Methodologies
Rapid Application Development (RAD)
RAD-based methodologies adjust the SDLC phases to get some part of system developed quickly and into the hands of the users.
Most RAD-based methodologies recommend that analysts use special techniques and computer tools to speed up the analysis, design, and implementation phases, such as CASE (computer-aided software engineering) tools.
Avicenna
System Analysis and Design System Analysis

16. Systems Development Methodologies
Rapid Application Development (RAD)
Five key factors
Extensive user involvement
Joint Application Design sessions
Prototyping
Integrated CASE tools
Code generators
Avicenna
System Analysis and Design System Analysis

17. Systems Development Methodologies
Rapid Application Development (RAD)
RAD is a general strategy rather than a single methodology
Goals
To analyze a business process rapidly
To design a viable system solution through intense cooperation between users and developers
To get the finished application into the hands of the users quickly
Traditional SDLC steps are followed, but phases are combined
Iteration is limited to design and development phases
Avicenna
System Analysis and Design System Analysis

18. Systems Development Methodologies (RAD) [2]
Advantages
Disadvantages
Dramatic time savings the systems development effort
More speed and lower cost may lead to lower overall system quality
Can save time, money and human effort
Danger of misalignment of system developed via RAD with the business due to missing information
Tighter fit between user requirements and system specifications
May have inconsistent internal designs within and across systems
Works especially well where speed of development is important
Possible violation of programming standards related to inconsistent naming conventions and inconsistent documentation
Ability to rapidly change system design as demanded by users
Difficulty with module reuse for future systems
System optimized for users involved in RAD process
Lack of scalability designed into system
Concentrates on essential system elements from user viewpoint
Lack of attention to later systems administration built into system
Strong user stake and ownership of system
High cost of commitment on the part of key user personnel
As you see there are many advantages for RAD and also many disadvantages but RAD still a good methodology to develop systems in less time with less cost
This is the end of our sequence today
Hope you enjoy it . See you next sequence
And now you can go to the formative assessment
Avicenna
System Analysis and Design System Analysis

19. System Analysis and Design System Analysis
Sequence Summary
A methodology is a formalized approach to implementing the SDLC.
Process centered methodologies, the focus is on defining the activities associated with the system.
Data centered methodologies focuses on defining the content of the data storage containers and how they are organized.
Object-oriented methodology attempts to balance the focus between processes and data.
waterfall development- based methodologies, the analysts and users proceed sequentially from one phase to the next.
Rapid application development (RAD) resembles a condensed version of the entire SDLC, with users involved every step of the way
Avicenna
System Analysis and Design System Analysis

20. System Analysis and Design System Analysis
Sequence Summary
In this Sequence we have
Defined the term development methodology
Explained the Characteristics of a Good Analysis Method
Explained Why Use a Methodology
Described the three categorizes of system development methodologies
Process-centered Methodologies
Data-centered Methodologies
Object-oriented methodologies
Explained Waterfall Development, Parallel Development, and rapid application development (RAD).
Avicenna
System Analysis and Design System Analysis

21. System Analysis and Design System Analysis
Reference
[1] System Analysis and Design, Sixth Edition
Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt
Publisher: SHELLY CASHMAN SEWIES.
[2] Modern Systems Analysis and Design Third Edition
Authors: Jeffrey A. Hoffer , Joey F. George, Joseph S. Valacich
Publisher: prentice hall
[3] System Analysis and Design, 3rd Edition
Authors: Dennis, Wixom, & Roth
Publisher: John Wiley & sons
Avicenna
System Analysis and Design System Analysis