Topic 3

• System life cycle


  The factoring of the lifetime of an information system into two stages: (1) systems development and (2) systems operation and maintenance
• System development methodology


  A formalized approach to the systems development process; a standardized development process that defines a set of activities, methods, best practices, deliverables, and automated tools that system developers and project managers are to use to develop and continuously improve information systems and software
• Principles of system development

  • Get the system users involved
  • Use a problem-solving approach
  • Establish phases and activities
  • Document through development
  • Establish standards
  • Manage the process and projects
  • Justify systems as capital investments
  • Don't be afraid to cancel or revise scope
  • Divide and conquer
  • Design systems for growth and change
• Classical problem-solving approach


  1. Study and understand the problem, its context, and its impact

  2. Define the requirements that must be met by any solution

  3. Identify candidate solutions that fulfill the requirements, and select the "best" solution

  4. Design and/or implement the chosen solution

  5. Observe and evaluate the solution's impact, and refine the solution accordingly
• Process management

  An ongoing activity that documents, manages, oversees the use of, and improves an organization's chosen methodology (the "process") for system development
• Project management


  The process of scoping, planning, staffing, organizing, directing, and controlling a project to develop an information system at a minimum cost, within a specified time frame, and with acceptable quality
• Cost-effectiveness


  The result obtained by striking a balance between the lifetime costs of developing, maintaining, and operating an information system and the benefits derived from that system
• Strategic information systems plan

  A formal strategic plan (3-5 years) for building and improving an information technology infrastructure and the information system applications that use that infrastructure
• Strategic enterprise plan


  A formal strategic plan (3-5 years) for an entire business that defines its mission, vision, goals, strategies, benchmarks, and measures of progress and achievement
• Creeping commitment


  A strategy in which feasibility and risks are continuously reevaluated throughout a project. Project budgets and deadlines are adjusted accordingly
• Risk management


  The process of identifying, evaluating, and controlling what might go wrong in a project before it becomes a threat to the successful completion of the project or implementation of the information system
• Problem


  An undesirable situation that prevents the organization from fully achieving its purpose, goals, and/or objectives
• Opportunity


  A chance to improve the organization even in the absence of an identified problem
• Directive


  A new requirement that is imposed by management, government, or some external influence
• Information systems strategy plan


  Has examined the business as a whole to identify those system development projects that will return the greatest strategic (long-term) value to the business
• Business process redesign


  Has thoroughly analyzed a series of business processes to eliminate redundancy and bureaucracy and to improve efficiency and value added
• Steering committee


  An administrative body of system owners and information technology executives that prioritizes and approves candidate system development projects
• Backlog


  A repository of project proposals that cannot be funded or staffed because they are a lower priority than those that have been approved for system development
• PIECES problem-solving framework

  • Performance
  • Information
  • Economics
  • Control
  • Efficiency
  • Service
• Problem statement


  A statement and categorization of problems, opportunities, and directives; may also include constraints and an initial vision for the solution
• Constraint


  Any factor, limitation, or restraint that may limit a solution or the problem-solving process
• Scope creep


  A common phenomenon wherein the requirements and expectations of a project increase, often without regard to the impact on budget and schedule
• Statement of work


  A contract with management and the user community to develop or enhance an information system; defines vision, scope, constraints, high-level user requirements, schedule, and budget
• Logical design


  The translation of business user requirements into a system model that depicts only the business requirements and not any possible technical design or implementation of those requirements
• System model


  A picture of a system that represents reality or a desired reality. System models facilitate improved communication between system users, system analysts, system designers, and system builders
• Analysis paralysis


  A satirical term coined to describe a common project condition in which excessive system modeling dramatically slows progress toward implementation of the intended system solution
• Candidate solutions evaluated in terms of

  • Technical feasibility
  • Operational feasibility
  • Economic feasibility
  • Schedule feasibility
  • Risk feasibility
• Physical design


  The translation of business user requirements into a system model that depicts a technical implementation of the users' business requirements
• System components constructed and tested

  • Software (purchased, custom-built)
  • Databases
  • User and System Interfaces
  • Hardware
  • Networks
• Deliver the system into operation (production)

  1. Deliver User training

  2. Deliver completed documentation

  3. Convert existing data
• System support


  The ongoing technical support for users of a system, as well as the maintenance required to deal with any errors, omissions, or new requirements that may arise
• Waterfall development approach


  An approach to systems analysis and design that completes each phase one after another and only once
• Iterative development approach


  An approach to systems analysis and design that completes the entire information system in successive iterations. Each iteration does some analysis, some design, and some construction
• Model-driven development


  A system development strategy that emphasizes the drawing of system models to help visualize and analyze problems, define business requirements, and design information systems
• Process modeling


  A process-centered technique popularized by the structured analysis and design methodology that used models of business process requirements to derive effective software designs for a system
• Data modeling


  A data-centered technique used to model business data requirements and design database systems that fulfill those requirements
• Object modeling


  A technique that attempts to merge the data and process concerns into singular constructs called objects. Object models are diagrams that document a system in terms of its objects and their interactions
• Logical model


  A pictorial representation that depicts what a system is or does
• Physical model


  A technical pictorial representation that depicts what a system is or does and how the system is implemented
• Automated tools for system development

  • Computer-aided systems engineering (CASE)
  • Application development environments (ADEs)
  • Process and project managers