IS 3003 Chap 11

  1. software that is correctly can transform
    as the organization and its business transforms.
  2. software that meets employees needs
    will help an organizationbecome more productive and enhance decision making
  3. software that does NOT meet employee needs have a damaging effect
    on productivity and can help business fail
  4. as organizations reliance grow on sw grows so do the business related consequences of sw successes and failures includes:
    • -increases or decreases revenue
    • -repair or damage brand reputation
    • -prevent or incur liabilities
    • -increase or decrease liability
  5. system failure can happen for several reasons
    • -missed deadlines
    • -users needs that werent met
    • -unclear or missing business requirements
    • -dissatisfied customers
    • -lack of support from top management
    • -going over budget
    • -others
  6. the problem solving process can be used to build new information systems
    • four steps building info systems:
    • -define and understand the problem
    • -develop alt solutions
    • -choose a solution
    • -implement the solution

    • first three steps are called system analysis
    • last one is called systems design
  7. Problem solving
    DEFINE
    •What caused the problem?


    •Why does it persist?


    •Why hasn’t it been solved?


    •What are the objectives of a solution?


    •Conduct a Requirements Analysis to determine the Information Requirements of the new system – who needs what information, where, when and how; the detailed set of business requests that the system must meet in order to be successful and meet objectives
  8. Problem solving

    DEVELOP
    •Develop alternative solutions to achieve the objectives and Information Requirements that were identified


    • Some solutions do not require an information system.


    •Some solutions require modification of existing systems.


    •Some solutions require new systems
  9. Problem Solving

    CHOOSING /ALT
    •Conduct a Feasibility Study to determine whether each alternative is feasible and achievable


    •Economic/financial, technical, operational, schedule, legal


    •Costs and benefits


    •Advantages and disadvantages


    •Business value of each system


    •Amount of change required and change management issues
  10. Problem Solving

    Implementation
    •Systems design stage


    •System design is the detailed design, model or blueprint for the system solution


    •Includes:


    •Hardware selection and acquisition


    •Software development and programming


    •Testing-system is thoroughly tested to determine it produces the right results/output




    •Training and documentation


    •Conversion


    •Production and maintenance


    •Managing the change







    Testing – system is thoroughly tested to determine it produces the right results/output



    Unit testing – detailed testing of individual computer programs or modules


    System testing – tests the performance of the information system as a whole


    •Acceptance testing – tests that the system is ready to be used in a production or “real” setting


    • Training and Documentation

    • Training:
    • •For successful implementation to occur, users will require training so they will be able to use the new system
    • •Different types of training are available: on-line, face-to-face, built-in “help” features, etc.

    • Documentation –
    • Shows how the system works from both a technical and end-user perspective
    • User manuals and reference guides
    • •Installation procedures
    • •Troubleshooting guides and procedures


    Conversion the process of changing from the old system to the new system

    •Parallel conversion – using both old and new systems until it is evident that the new system performs correctly


    •Plunge (direct cutover) conversion – discard old system completely and start using new system


    •Pilot conversion – implement new system in one department or location only until it is evident that the new system works


    •Phased conversion – implement new system in phases or pieces



    • Production and Maintenance
    • Production
    • - the actual use of the system in the real world setting
    • - ongoing review of the system to determine how well it is meeting the Information Requirements and objectives to determine if any modifications are needed

    • Maintenance
    • - changes required to correct or enhance a system
    • - different types of maintenance ….


    • Types of Maintenance

    Corrective maintenance – repair defects or flaws in the design, coding or implementation


    Adaptive maintenance – increase system functionality to meet new business requirements

    • Perfective maintenance – enhancements or improvements; desired but not necessarily required features

    Preventative change- changes to reduce the chance of system failure


    • Managing the Change - Implementation of a new system will bring about other organizational changes
    • Change management – a set of techniques that aid in evolution, composition, and policy management of the design and implementation of a system


    Change management system – a collection of procedures to document a change request and define the steps necessary to consider the change based on the expected impact of the change


    Change control board (CCB) – responsible for approving or rejecting all change requests
  11. Alternative systems building apporaches.

    Traditional Systems Development Lifecycle (SDLC
    •Oldest method for building information systems


    •Phased approach with formal stages


    •Waterfall approach


    •Formal division of labor


    •Used for building large, complex systems


    •Time consuming and expensive to use
  12. Alternative systems building approaches

    Protyping
    •Preliminary model built rapidly and inexpensively; a small scale version of the system


    •Four-step process


    •Identify the user’s basic requirements.


    •Develop an initial prototype.


    •Use the prototype.


    •Revise and enhance the prototype.


    •Is large enough to illustrate the system’s features & benefits and allow users to offer feedback to make changes
  13. alternative systems building approaches-

    END USER DEVELOPMENT
    •End users create simple information systems with little or no assistance from technical specialists.


    •Use fourth-generation languages, graphics languages, and PC software tools to access data, create reports, and develop information systems.


    •Reduce time and steps required to produce the system


    •More “customized” to user needs


    •Organizational risks
  14. alternative systems buildig approaches

    Purchasing Solutions
    Purchase a software package from a commercial vendor


    •Generalized systems for universal functions with standard processes


    •Customization


    •Rent/lease the software from an Application service provider (ASP)


    •Outsource development of the software to an outside firm
  15. Outsourcing Options
    Onshore outsourcing – engaging another company within the same country for services


    •Nearshore outsourcing – contracting an outsourcing arrangement with a company in a nearby country


    •Offshore outsourcing – using organizations from developing (or far-shore) countries to write code and develop systems
  16. alternative systems building approaches

    RAD-Rapid Application Development
    •Focus on agility and scalability


    •Creating workable systems in a very short period of time


    •Utilize prototyping, reusable standardized SW components, and JAD techniques


    •May include Joint application design (JAD)


    •End users and information systems specialists working together on design
  17. Alternative methodologies for modeling and designing systems:
    •Structured methodologies


    •Object-oriented development


    •Computer-aided software engineering (CASE)
  18. alternative methods for modeling and designing systems


    •Structured methodologies
    •Data flow diagram – represents the processes of a system and the flow of data between them


    Process specifications – describe the transformation occurring within the lowest level of the data flow diagrams, showing the logic for each process


    •Structure chart – a top-down chart showing each level of design, its relationship to other levels, and its place in the overall design structure
  19. Data Flow Diagram for Mail-in University Registration System
    The system has three processes: Verify availability (1.0), Enroll student (2.0), and Confirm registration (3.0). The name and content of each of the data flows appear adjacent to each arrow. There is one external entity in this system: the student. There are two data stores: the student master file and the course file.
  20. alternative methodolgies for modeling and designing systems

    OBJECT ORIENTED DEVELOPMENT
    •Uses the concept of an “object” as the basic unit of analysis and design – an object combines the data and the specific processes that operate on that data


    •The system is modeled as a collection of objects and the relationships among them


    •Based on concepts of class and inheritance


    •Objects belonging to a certain class have the features of that class


    •Classes of objects inherit the structure and behaviors of the general class they belong to


    •Component-based development and Web services – a way to develop SW by using SW components for common functions to quickly develop systems
  21. modeling and designing systems

    CASE

    Computer Aided Software Engineering
    •Provides software tools to automate the previously described methodologies


    •Reduces repetitive work in systems development





    •CASE tools facilitate clear documentation and coordination of team development efforts


    •Productivity benefits
  22. Project Management
    • •Project

    •Planned series of related activities for achieving a specific business objective


    • •Project Management

    •Application of knowledge, skills, tools, and techniques to achieve targets within specified budget and time constraints


    • •Project Management Variables:

    •Scope


    •Time


    •Cost


    •Quality


    •Risk



    • Must select the projects to pursue – evaluate and compare the choices




    •Determine project costs and benefits


    •Tangible benefits


    •Intangible benefits


    •Capital budgeting methods – ROI, NPV, IRR


    •Evaluate fit with your Information Systems Plan


    •Portfolio analysis


    •Scoring model







    • •Level of project risk is affected by:

    •Project size


    •Project structure


    •Required level of technical expertise



    • •Implementation and change management

    Implementation – the more users can be involved in the development of a system, usually the higher the success rate


    •User-designer communications gap – can exist and negatively affect project success however ….






    • •Overcoming user resistance

    •Promote user participation


    •Pay attention to user interfaces and ergonomic issues


    •Conduct an Organizational Impact analysis


    • •Controlling risk factors

    •Formal planning and tools


    Gantt Chart – lists project activities along with their start and completion dates – visually represents the timing and duration of different tasks


    •PERT chart – graphically depicts the project tasks and their interrelationships/dependencies









    •Project challenges for global systems are complicated by international environment


    •User info requirements, business processes, work cultures vary from country to country


    • •Ways of convincing users to adopt global systems:

    •Permitting each country unit in a global corporation to develop one application in its home country first.


    •Develop transnational centers of excellence to perform business and systems analysis, design, testing.
Author
monaben20
ID
121950
Card Set
IS 3003 Chap 11
Description
IS 3003 Chap 11
Updated