System development

• are not clearly defined
• SYSTEM DEVELOPMENT


  1. Set of items, equipments, procedures, processes, programs and people working jointly

  2. With an aim of achieving common goals
• System


  A set of organized components which interact in a given goal and objectives and with a specified boundary
• Examples of systems


  • Education (school) system
  • Transport system
  • Banking system
• Components of a system

  • To identify or correct any errors
  • State areas of feedback in a system
  • Helps the user to determine if the input affects output
  • Determine if the item is meeting the initial objectives
• A system does some useful job, hence, it should be active and efficient
• Soft system


  • Human activity systems
  • Their boundaries keep on changing
  • Their goals and objectives usually conflict
  • Difficult to clearly define their exact measures of performance
• Examples of soft systems

  • Political system
  • Sales tracking and prediction system in an organization
• Hard systems


  • Systems whose goals and objectives are clearly defined
  • The outcome from their processes are predictable and can be modeled accurately
  • Based on proven scientific laws such as mathematical formulas
• Open/Closed system


  Engineering solutions that support and improve day-to-day operations in a business
• Information System


  To support information processing tasks such as data collection, storage, processing and reporting
• Purposes of an Information System

  • Supports information sharing between departments
  • Helps in decision making by collecting data, organizing it and giving reports
  • Provides a chance to improve internal processes
  • Enables rapid insertion of new systems
• Reasons for developing an Information System

  • Problems in the existing system
  • Directives
  • Tradition
  • Opportunities that are more successful than existing systems
  • Free of poor performance which increases the level of indirect expenses
• System analysis and design

  1. System analysis - Collecting and analysing facts that relate to an existing situation

  2. System design - Identifying possible solutions to a problem and deciding the most appropriate
• System analyst


  Person who identifies a problem and designs to solve the problems
• Roles of a System analyst

  • Reviews the existing system and makes recommendations
  • Works with programmers to construct a computerised system
  • Co-ordinates the training of new system users and system buyers
  • Project manager of the information system being implemented
• Waterfall model


  • Not a good model for complex projects
  • Poor model for long range in-house projects
  • System performance cannot be tested until the implementation is complete
  • Cannot accommodate changing requirements
  • Rigid model due to its sequential nature
• 1. shaped model


  • Requirement definition
  • System specification
  • High level design
  • Detailed design
  • Construction (coding)
  • Unit testing
  • Integration testing
  • System testing
• Advantages of V-shaped model

  • Easy to manage
  • Simple and easy to understand and use
  • Works well for small projects
  • Highly disciplined model because phases are completed at a time
• Disadvantages of V-shaped model

  • Not a good model for complex projects
  • Poor model for ongoing projects
  • Not suitable for projects at a higher risk of changing requirements
  • No working software is produced until late during the life cycle
• Rapid Application Development (RAD)


  • Highly iterative approach that attempts to address most of the weaknesses of structured methodologies
  • Prototyping - performing the early design and implemented on concurrently and repeatedly until the final system is completed
• Phased development


  1. The analysis phase identifies the system concept and then categorizes the requirements

  2. The design phase is used to develop the initial version of the system

  3. The implementation phase is used to develop the current version based on a set of requirements identified for the current version
• Advantages of Phased development

  • Increased productivity with fewer people in a short time
  • Provides technical feasibility
  • Provides economic feasibility
  • Provides schedule feasibility
• Information gathering


  1. Documents review

  2. Interviews

  3. Questionnaires

  4. Observation
• Advantages of Interviews


  • Non verbal communication can be used and observed
  • Questions can be rephrased instantly for clarification and to probe the interviewee further
  • Makes the interviewee feel like part of the system
• Disadvantages of Interviews


  • Time consuming
  • Interviewees give answers which are not proven fact but opinion
  • Interviewees may be suspicious of the intentions of the proposed system
  • The interviewee may not fully open up on some issues
• Advantages of Questionnaires


  • Limited information required from a large number of people
  • Respondents can fill the questionnaire at their own convenience
  • Provides an opportunity to provide input to many people
  • Saves time
• Disadvantages of Questionnaires


  • Designing requires expertise
  • Questions may be misunderstood leading to ambiguous replies
  • Analysis requires a lot of time
• Advantages of Observation


  • Gives first-hand information
  • Concepts that can the difficult can be explained
  • Helps analysts become acquainted with operational personnel
  • Helps analysts acquire 'know how' needed to assist in changes that have been recommended
  • Can correct hazy understanding and erroneous impressions
• Disadvantages of Observation


  • Consumes a lot of time
  • It is costly
  • Staff members are not comfortable being watched
  • Person being observed might change their behaviour
• Automated methods are used when data is required but difficult to get through interviews, observation, questionnaires e.g. Computer logs, Video, Tape recording
• Preparing data collection report

  1. Letter addressed to management

  2. Table of contents

  3. Executive summary which provides a snapshot of how the new system is implemented

  4. Outline of feasibility study which provides information about all methods used in the study

  5. Detailed results of the study

  6. Conclusions and recommendations
• Requirement specification


  • Output specification
  • Input specification
  • Field to pass
  • Hardware and software requirement
  • Procuring tasks
• consumes a let of there
• (6) H is castly
• (i) Storff members are not comfortable being watched
• (*) Person being observed might change their behourur
• Automated method


  When data is required but difficult to get through
• observation


  Cover er questionnons eg Compras Video Top recording
• Preparing date collection report

  1. letter addressed to management

  2. who collected data

  3. 2 Tale page & submitted

  4. Table of antet

  5. Expartive summary which provides

  6. Implemented

  7. S Outline

  8. and task force written by the pris

  9. mapshot of how to new system is

  10. touch of feartibilly study which provide information about

  11. all methods used in the study

  12. Detailed results of the study

  13. 7 Conclusions and recommendations