System Analysis Design Mr Ahmad AlGhoul learning Objectives

System Analysis & Design - Mr. Ahmad Al-Ghoul

learning Objectives n n Explain joint application development (JAD) Explain Prototyping-based methodologies Avicenna System Analysis and Design System Analysis 2

introduction n n JAD (Joint Application Development) is a methodology that involves the client or end user in the design and development of an application, through a succession of collaborative workshops called JAD sessions. System development personal at IBM developed JAD in the late 1970 s and began teaching the approach through workshops in 1980 As systems grew in size and complexity, it become impossible to make it one-shot pass through stages. Developers were always looping back and reading things to come up with a system that satisfied the users. In response to this limitation, system developers apply a technique called prototype. Prototype provides the developers and future users with an idea of how the system in its completed form will function Avicenna System Analysis and Design System Analysis 3

Systems Development Methodologies n Joint Application Development (JAD) n n n Joint Application Development (JAD) can replace a series of interviews with the user community JAD is a technique that allows the analyst to accomplish requirements analysis and design the user interface with the users in a group setting Brings together key users, managers and systems analysts Purpose: collect system requirements simultaneously from key people Objective is to analyze the existing system, obtain user input and expectations, and document user requirements for the new system End Result n n Avicenna Documentation detailing existing system Features of proposed system System Analysis and Design System Analysis 4

Systems Development Methodologies n JAD Participants and Roles n n Avicenna During the development process, the IT staff would collect information from users, define system requirements, and construct the new system At various stages of the process, the IT staff might ask users to review the design, offer comments, and submit changes IT professionals now recognize that successful systems must be user oriented, and user need to be involved, formally or informally, at every stage of system development One popular strategy for user involvement is a JAD team approach, which involves a task force of users, managers, and IT professionals that work together to gather information, discuss business need, and define the new system requirements System Analysis and Design System Analysis 5

Systems Development Methodologies n JAD Participants and Roles n n n Avicenna A (JAD) team usually meets over a period of days or weeks in special conference room or at an off-site location JAD participants should be insulated from the distraction of day-to-day operations Objective is to analyze the existing system, obtain user input and expectations, and document user requirements for the new system System Analysis and Design System Analysis 6

Systems Development Methodologies n JAD participants and roles Project leader n Top management n Managers n Users n Systems analysts and other IT staff members n recorder n Avicenna System Analysis and Design System Analysis 7

Systems Development Methodologies n JAD participants and roles n Project leader n n Top management n n Provide enterprise level authorization and support for the project managers n Avicenna Project leader develop an agenda, acts as facilitators, and leads the JAD session Provide department level support for the project and understanding of how the project must support business functions and requirements System Analysis and Design System Analysis 8

Systems Development Methodologies n JAD participants and roles n Users n n Systems analysts and other IT staff members n n Provide technical assistance and resources for JAD team members on issues such as security, backup, hardware, software, and network capability Recorder n Avicenna Provide operational level input on current operations, desired changes, input and output requirements, user interface issues, and how the project will support day-to-day tasks Documents results of JAD sessions and work with system analysts to build system models and develop CASE tool documentation System Analysis and Design System Analysis 9

Systems Development Methodologies n Preparing for the JAD Sessions Time commitment – ½ day to several weeks n Strong management support is needed to release key participants from their usual responsibilities n Careful planning is essential n Avicenna System Analysis and Design System Analysis 10

Systems Development Methodologies n Typical JAD session agenda Avicenna System Analysis and Design System Analysis 11

Systems Development Methodologies n JAD Advantages and Disadvantages n Advantages n n n Disadvantages n Avicenna Allows key users to participate effectively When properly used, JAD can result in a more accurate statement of system requirements, a better understanding of common goals, and a stronger commitment to the success of the new system More expensive and can be cumbersome if the group is too large relative to the size of the project System Analysis and Design System Analysis 12

Systems Development Methodologies n Prototyping methodology perform the analysis, design and implementation phases concurrently. n All three phases are performed repeatedly in a cycle until the system is completed. n A prototype is a smaller version of the system with a minimal amount of features. n Avicenna System Analysis and Design System Analysis 13

Systems Development Methodologies n Prototyping methodology n n n Quickly converts requirements to working version of system Once the user sees requirements converted to system, will ask for modifications or will generate additional requests Most useful when: n n n Avicenna User requests are not clear Few users are involved in the system Designs are complex and require concrete form History of communication problems between analysts and users Tools are readily available to build prototype System Analysis and Design System Analysis 14

Systems Development Methodologies n Prototyping methodology n n Types of prototypes Prototype are of two types n Evolutionary n n A requirements prototype n n Avicenna Evolutionary prototype is continually refined until it contains all of the functionality that the users require of the new system Developed as a way to define the functional requirements of the new system when the users are unable to determine exactly what they want A requirements prototype review the requirements, features are added, users are able to define the processing required for the new system System Analysis and Design System Analysis 15

Systems Development Methodologies n Prototyping methodology n Development of an Evolutionary Prototype 1. 2. 3. 4. Avicenna Identify user needs: the developer interviews users to obtain an idea of what is required from the system Develop a prototype: the developer uses one or more prototyping tools to develop a prototype Determine if the prototype is acceptable: the users decide if the prototype is satisfactory or not. If not the prototype is go back to the step one Use the prototype: the prototype becomes the production system System Analysis and Design System Analysis 16

Systems Development Methodologies n Prototyping methodology n n Development of a Requirements Prototype The first three steps to develop a requirements prototype are the same as those taken to develop an evolutionary prototype. The next steps are as follows 4. 5. 6. 7. Avicenna Code the new system: the developer uses the prototype as the basis for coding the new system Test the new system Determine if the new system is acceptable: the users advises the developer whether the system is acceptable or not. If not go back to step four Put the new system into production System Analysis and Design System Analysis 17

Systems Development Methodologies n Prototyping methodology n Advantages: n n n Disadvantages: n n Avicenna Most important functionalities are considered as and when they arrive Consistency between requirements is checked in each iteration Customers feel the progress of the development process Developer can use the prototype in any iteration as a source for winning customer contracts Identifying the most important subset of requirements at any stage is a tedious task Establishing consistency in each iteration is a repetitive work, particularly when new subset of requirements bear no relationships with the existing ones Sharing data with other systems is often not considered Project deadline cannot be estimated System Analysis and Design System Analysis 18

Systems Development Methodologies [3] Prototyping-based methodologies Avicenna System Analysis and Design System Analysis 19

Sequence Summary n n A joint application development (JAD) is a teambased approach to fact finding and requirements modeling. JAD involves an interactive group of users, managers, and IT professionals who participate in requirements modeling and develop a greater commitment to the project and to their common goals In prototyping, a trial system is developed quickly and presented to the user for review. Refinement are made based on the review, and this process is repeated until the prototype is approved by the user. Avicenna System Analysis and Design System Analysis 20

Sequence Summary n In this Sequence we have n n n n Avicenna Explained joint application development (JAD) Addressed JAD Participants and their roles Discussed how to prepare for JAD sessions Explained JAD advantages and disadvantages Explained Prototyping-based methodologies Explained when to use prototyping-based methodologies Distinguished between Evolutionary prototype and Requirements Prototype Explained prototyping methodologies advantages and disadvantages System Analysis and Design System Analysis 21

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, 3 rd Edition Authors: Dennis, Wixom, & Roth Publisher: John Wiley & sons [4] Management Information Systems, tenth Edition Authors: Raymond Mcleod, Jr. & George P. Schell Publisher: prentice hall Avicenna System Analysis and Design System Analysis 22