System Analysis

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System Analysis Design
System Analysis and Design

• - Mr. Ahmad Al-Ghoul

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learning Objectives

• Explain joint application development (JAD)
• Explain Prototyping-based methodologies

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introduction

• 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 1970s 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

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Systems Development Methodologies

• Joint Application Development (JAD)
• 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
• Documentation detailing existing system
• Features of proposed system

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Systems Development Methodologies

• JAD Participants and Roles
• 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

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Systems Development Methodologies

• JAD Participants and Roles
• 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

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Systems Development Methodologies

• JAD participants and roles
• Project leader
• Top management
• Managers
• Users
• Systems analysts and other IT staff members
• recorder

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Systems Development Methodologies

• JAD participants and roles
• Project leader
• Project leader develop an agenda, acts as
  facilitators, and leads the JAD session
• Top management
• Provide enterprise level authorization and
  support for the project
• managers
• Provide department level support for the project
  and understanding of how the project must support
  business functions and requirements

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Systems Development Methodologies

• JAD participants and roles
• Users
• 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
• Systems analysts and other IT staff members
• Provide technical assistance and resources for
  JAD team members on issues such as security,
  backup, hardware, software, and network
  capability
• Recorder
• Documents results of JAD sessions and work with
  system analysts to build system models and
  develop CASE tool documentation

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Systems Development Methodologies

• Preparing for the JAD Sessions
• Time commitment ½ day to several weeks
• Strong management support is needed to release
  key participants from their usual
  responsibilities
• Careful planning is essential

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Systems Development Methodologies

• Typical JAD session agenda

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Systems Development Methodologies

• JAD Advantages and Disadvantages
• Advantages
• 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
• Disadvantages
• More expensive and can be cumbersome if the group
  is too large relative to the size of the project

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Systems Development Methodologies

• Prototyping methodology
• Prototyping methodology perform the analysis,
  design and implementation phases concurrently.
• All three phases are performed repeatedly in a
  cycle until the system is completed.
• A prototype is a smaller version of the system
  with a minimal amount of features.

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Systems Development Methodologies

• Prototyping methodology
• 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
• 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

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Systems Development Methodologies

• Prototyping methodology
• Types of prototypes
• Prototype are of two types
• Evolutionary
• Evolutionary prototype is continually refined
  until it contains all of the functionality that
  the users require of the new system
• A requirements prototype
• 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

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Systems Development Methodologies

• Prototyping methodology
• Development of an Evolutionary Prototype
• 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

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Systems Development Methodologies

• Prototyping methodology
• 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
• 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

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Systems Development Methodologies

• Prototyping methodology
• Advantages
• 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
• Disadvantages
• 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

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Systems Development Methodologies 3
Prototyping-based methodologies
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Sequence Summary

• A joint application development (JAD) is a
  team-based 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.

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Sequence Summary

• In this Sequence we have
• 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

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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
• 4 Management Information Systems, tenth Edition
• Authors Raymond Mcleod, Jr. George P.
  Schell
• Publisher prentice hall