ACCOUNTING INFORMATION SYSTEMS Core Concepts of ACCOUNTING INFORMATION SYSTEMS Moscove, Simkin & Bagranoff Developed by: S. Bhattacharya, Ph.D. Florida Atlantic University John Wiley & Sons, Inc.
Chapter 12 Systems Study: System Design and Selection Introduction The Feasibility Evaluation Detailed Systems Design Selecting a Final System
Introduction If the client’s steering committee reacts positively toward the recommendations, the organization moves forward with systems design. Prior to preparing a detailed design for a computerized information system, the consultants should conduct a feasibility evaluation.
The Feasibility Evaluation In a feasibility evaluation, the design team determines the practicality of alternative proposals. For each system alternative, the design team must examine five feasibility areas: Technical Operational Schedule Legal Economic
Steps in the Systems Design Phase of a Systems Study Buy Make
Steps in the Systems Design Phase of a Systems Study Perform feasibility evaluation Prepare detailed systems design Prepare systems specifications report Submit systems specifications report to computer vendors or internal IT department. Select particular computer vendor proposal or develop application in-house.
Technical Feasibility The technical feasibility of any proposed system attempts to answer the question: “What technical resources are required by a particular system?” Hardware and software are two components of the question. Need to also determine if current employees possess the technical skills.
Operational Feasibility The operational feasibility of any proposed system attempts to answer the question: “How consistent will the tasks and procedures of the new system be with those of the old system?” Operational feasibility is mostly a human relations study because it is strongly oriented toward “people problems.”
Schedule Feasibility Schedule feasibility involves estimating how long it will take a new or revised system to become operational and communicating this information to the steering committee.
Legal Feasibility Legal feasibility is largely concerned with whether there will be any conflict between a newly proposed system and the organization’s legal obligations. Revised systems should comply with applicable federal and state statutes about financial reporting and other contractual obligations.
Economic Feasibility Economic feasibility focuses on projecting which, if any, of the proposed computerized systems are expected to be cost-effective. The design team should perform a cost-benefit analysis on each proposed system. A cost-effective system is one whose anticipated benefits are expected to exceed its anticipated costs.
Costs and Benefits Projected costs and benefits are often converted to their present values by using capital budgeting techniques. The benefits of a computerized data processing system are often difficult to quantify monetarily. The costs are usually based on accountant’s estimates.
Examples of Costs and Benefits Benefits of a system Reduced Clerical Costs Enhanced Sales Better Customer Service Costs of a system Initial Computer Hardware and Software Additional IT Staff Operation Costs
Final Feasibility Report The design team will make complete feasibility evaluations for each system proposal. When the team completes evaluations, it submits a final feasibility report to the steering committee. This report summarizes its work and makes recommendations.
Detailed Systems Design Consultants prepare a Detailed System Design for the general systems plan. Detailed System Design includes specifying outputs, processing procedures, and inputs for the new system. This becomes the “blueprint” for creating or acquiring the new system.
Examples of Detailed Requirements for a System Proposal Processes Data Elements Data Structure Inputs Outputs Documentation Constraints Controls Reorganizations
Designing System Outputs An AIS should be designed to meet users’ information needs; thus, output specifications must by prepared first. The design team should use data gathered from the prior systems analysis work to help decide what kinds of reports are needed. Outputs should be classified according to functional area requesting them.
Process Design Process design involves identifying the processing procedures required to produce the outputs. Tools available to model processes are ER diagrams, structure charts, system flowcharts, data flow diagrams, program flowcharts, and process maps. Common to all of these design methodologies is the idea of a structured, top-down design.
Process Design Object-oriented design methods are gaining popularity because: They employ the Unified Modeling Language They are especially adapted to designing the event-driven systems Case Tools assist systems designers in drawing various diagrams and charts.
Designing System Inputs Team must identify and describe each data element in the systems design as well as specify the way data items must be coded. The design team must also determine the source for each data element.
Prototyping Prototyping means developing a simplified working model, or prototype, of a proposed information system. The prototype is scaled-down and experimental. It is built quickly with minimal expense.
Prototyping Development Steps Identify information systems requirements Develop initial prototype Test and revise Obtain user signoff of the approved prototype
Advantages of Prototyping Results in better definition of users’ needs and requirements than does the traditional systems development approach Can be developed in short period of time Errors detected and eliminated early in the development process
Disadvantages of Prototyping Users may not be willing to devote extensive time to experimenting with prototype. May result in inadequate testing and documentation. May cause behavioral problems with system users.
Systems Specifications Report The Systems Specifications Report includes detailed information about the system design proposal. After the steering committee approves the detailed design work, it now faces a make-or-buy decision.
Information Included in Systems Specification Report Historical background information about company’s operating activities Detailed information about the problems in the company’s current data processing system Detailed descriptions of the systems design proposals Indication of what the vendors should include in their proposals Time schedule for implementing the new system
Key Factors in Selection of Vendor Proposals The performance capability of each proposed system in relation to its cost. The costs and benefits of each proposed system. The maintainability of each proposed system. The compatibility of each proposed system with existing systems. Vendor Support
Making a Final Decision Point-Scoring Analysis can be used to evaluate packages that meet most of a company’s major requirements. Evaluation committee assigns potential points to each of the evaluation criteria based on its relative importance. Provides an object means of selecting final system.
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Chapter 12