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Chapter 10. Systems Planning and Analysis. Describe the relationship of systems analysis to systems development as a whole. Learning Objective 1. Overview of Systems Planning and Analysis. Systems planning involves identifying subsystems within the information system.
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Chapter 10 Systems Planning and Analysis
Describe the relationship of systems analysis to systems development as a whole. Learning Objective 1
Overview of SystemsPlanning and Analysis Systems planning involves identifying subsystems within the information system. Systems analysis begins after systems planning has identified subsystems for development.
Overview of SystemsPlanning and Analysis • Objectives of Systems Analysis • 1. Gain an understanding of the existing system (if one exists). • 2. Identify and understand problems. • 3. Express identified problems in terms of information needs • and system requirements. • 4. Clearly identify subsystems to be given highest priority. • Focus • Identify critical success factors. • Give special attention to these factors.
Overview of SystemsPlanning and Analysis Cost Patterns at Varying Development Stages Cost in Dollars Systems Analysis Systems Design Systems Implementation
Systems Planning andFeasibility Analysis Phases 1. Discussing and planning on the part of top management 2. Establishing a systems planning steering committee 3. Establishing overall objectives and constraints 4. Developing a strategic information systems plan
Systems Planning andFeasibility Analysis Phases 5. Identifying and prioritizing specific areas within the organization for the systems development focus 6. Setting forth a systems proposal. 7. Assembling a team of individuals for purposes of the analysis and preliminary systems design
Systems Planning andTop Management Steering Committee: Developing objectives and system constraints Developing a strategic systems plan Identifying individual projects for priority Commissioning the systems project
Describe the various stages of systems analysis. Describe some of the human problems involved in systems analysis. Learning Objectives 2 and 4
The Steps of Systems Analysis Step 2: Identify information needs Step 1: Survey current system Step 3: Identify systems requirements Step 4: Systems analysis report
Phase I: Survey the Present System What are the objectives of surveying? Gain a fundamental understanding of the operational aspects of the system. Establish a working relationship with users. Collect important data. Identify specific problems.
Management Phase I: Survey the Present System Communication Gap Problem Systems Analyst Job security Uncertainty Resistance to change
Phase I: Survey the Present System Approaches to Commmunication Gap: Get to know as many people involved in the system as soon as possible. Communicate the benefits of the proposed system.
Inside Outside Phase I: Survey the Present System Sources for gathering facts Analysis of survey findings
Phase II: IdentifyInformation Needs Information Needs Analysis: Identify the manager’s primary job responsibilities. Identify the means by which the manager is evaluated. Identify some of the major problems the manager faces. Identify the means by which the manager evaluates personal output.
Phase III: Identify theSystems Requirements Requirements: Inputs Outputs
Phase IV: Develop aSystems Analysis Report What are key elements of this report? A summary of the scope and purpose of the analysis project A reiteration of the relationship of the project to the overall strategic information systems plan A description of any overall problems in the specific subsystem being studied
Phase IV: Develop aSystems Analysis Report A summary of the decisions being made and their specific information requirements Specification of system performance requirements An overall cost budget and timetable Recommendations for improving the existing system and modifying objectives
Discuss the major techniques for gathering and organizing data for systems analysis. Learning Objective 3
Warnier–Orr Illustration Due date > = Discount = Determine today’s date percent × discount gross amount Compute Due date < Discount = 0 total amount today’s date due for invoices Amount due = (n) gross – discount Accumulate total amount due + Techniques for Fact Organization
Techniques for GatheringFacts for Analysis Depth interview Structured interview Open-ended questionnaire Closed-ended questionnaire Document reviews Observation
Techniques for Fact Organization Work measurement Work distribution Flow charting Decision analysis Functional analysis Hierarchical function Matrix analysis Narratives File/report summaries
Structured Systems Analysis This is an approach to systems analysis that begins with a general description of a particular system. Logical flow diagrams versus Flowcharts Systems design versus Systems analysis
Steps in StructuredSystems Analysis Develop logical data flow diagrams Define data dictionaries Define access methods Define process logic
Stores Purchase file Purchase details Requisition Purchase order Vendors Purchasing SystemContext Diagram Purchasing system
Expansion of PurchasingSystem Context Diagram Stores Purchase file Requisition details Requisition Validate requisition Purchase order Prepare purchase order Details Vendors
Structured English Access purchase file for each purchase requisition. IF account no. on requisition equals account-no-1 THEN flag account-no-1 field ELSE IF account no. on requisition equals account-no-2 THEN flag account-no-2 field ELSE (none of the above) SO void the transaction and generate error code
Describe the various steps involved in specifying systems design alternatives. Describe the content of a systems design proposal. Learning Objectives 5 and 7
Systems planning and analysis Systems Design Evaluate various designs 1 Prepare design specifications 2 Systems design specifications 3 Systems implementation Systems review and control Steps in Systems Design
Evaluating Design Alternatives What are some aspects of systems design? Enumeration of design alternatives Describing the alternatives Evaluating the alternatives Preparing design specifications
Control considerations Database design Specify processing Type of control Function of control Applicable systems component Specify inputs Design of System Elements Reports and other outputs
Preparing and Submitting Specifications What should the design proposal include? Specific timetables for completion Budget Description of personnel requirements Flowcharts Other diagrams Business process blue printing
Discuss the various considerations relevant to preparing design specifications. Learning Objective 6
System Element Design Consideration Outputs (report or document) Cost effectiveness Relevance Clarity Timeliness Design Considerations Database Cost effectiveness Integration Standardization Flexibility Security Accuracy Efficiency Organization
Design Considerations System Element Design Consideration Data processing Cost effectiveness Uniformity Integration Accuracy Data input Cost effectiveness Accuracy Uniformity Integration Controls and security measures Cost effectiveness Comprehensiveness Appropriateness
Summarize several major design techniques. Learning Objective 8
Design Techniques Forms design Database design Systems design packages
Discuss the usefulness of systems design packages. Learning Objective 9
Systems Design Packages CASE (computer-aided software engineering): Data flow diagrams Narrative documentation Screen and report prototypes Data dictionary descriptions
Choosing Software and Hardware What are some advantages of purchased software packages? They are cheaper. They are already debugged. Trials of the product can be made prior to investing a great deal of money.
Choosing Software and Hardware What is the main disadvantage of purchased software packages? They rarely exactly meet a company’s needs.
Choosing Software and Hardware It is usually safe to be content with the hardware on which that software runs. It is recommended to get machinery that is upwardly compatible.
Wild enthusiasm Disillusionment Total confusion “Real” Systems Life Cycle
Punishment of the innocent Promotion of nonparticipants “Real” Systems Life Cycle Search for the guilty
As proposed by the user manager As approved by the steering committee As structured by the data administrator Communication Problems in Systems Development
As designed by the lead analyst As implemented by the application programmers What the user actually wanted Communication Problems in Systems Development