Mis system analysis and system designPresentation Transcript
Group No. 3Bhuvan AryaAnoop ShetDeepak KhuntwalAmit SharmaKumar AnupamRahul Hedau
System analysis describes what a system should do tomeet the information needs of users.System design specifies how the system will accomplishthis objective.System design consists of design activities • that produce system specifications • satisfying the functional requirements • developed in the systems analysis stage.
Describe the strategic planning process, and why it is important to IT managers Explain the purpose of a mission statement Explain the SDLC as a framework for systems development and business modeling Explain the reasons for information systems projects and the factors that affect such projects
Describe the initial review of systems requests and the role of the systems review committee Describe the internal and external factors that affect information systems projects Define operational feasibility, technical feasibility, and economic feasibility Describe the steps and end product of a preliminary investigation
Systems planning tasks ◦ Examine the systems request ◦ Conduct a preliminary investigation ◦ Using SDLC and CASE tools to provide a framework
The SDLC is generally presented as an iterative sequence of five steps: ◦ Systems Planning ◦ Systems Analysis ◦ Systems Design ◦ Systems Implementation ◦ Systems Operation and Supporteach culminating in a deliverable, either a written document or a piece of software (or both)SDLC allows organizations to incorporate new requirements, technology and human resources to IT development
1. Systems Planning Project definition Feasibility study Project scope, deliverables Standards, techniques and methods Task assessment, skill assessment, preliminary time estimation2. Systems Analysis Analysis of existing hardware/software User requirements analysis Logical systems design: A. Conceptual data model B. Conceptual process model C. Functional application description
3. Systems Design Relational database model and data dictionary Detailed description of application inputs and outputs Detailed conceptual design of forms, reports, application programs and other application components4. Systems Implementation Application development Testing and Evaluation Yields Functional Information System5. Systems Operation and Support Maintenance Revisions Yields Operating Information System
Reasons for Systems Analysis ◦ Improved service ◦ Better performance ◦ More information ◦ Stronger controls ◦ Reduced cost
Overview of feasibility ◦ Feasibility study uses three main yardsticks: Operational feasibility Technical feasibility Economic feasibility
Operational feasibility ◦ Is the system a practical and effective approach? Operational feasibility depends on: ◦ Management and user support ◦ User involvement in planning ◦ Impact of performance on customers and company image ◦ Reasonable schedules
Technical feasibility ◦ Does the organization have resources to develop/purchase and operate the system? Technical feasibility depends on: ◦ Technical expertise within the organization ◦ Availability of necessary equipment ◦ Hardware and software reliability ◦ Adequate performance that will meet specifications ◦ Capacity for future needs/projected growth
Economic feasibility ◦ Do the projected benefits outweigh the estimated costs of development, installation, and operation? Economic feasibility depends on: ◦ Costs — one time and continuing costs ◦ Benefits — tangible and intangible benefits ◦ Timing of various costs and benefits ◦ Cost of not developing the system
Determining feasibility ◦ First step is a determination of feasibility ◦ Goal is to identify non-feasible projects as soon as possible ◦ Feasibility can change over time Non-feasible projects can be resubmitted Initially feasible projects can be rejected later
Criteria used to evaluate systems requests ◦ Reduce costs ◦ Increase revenue ◦ Produce more information or better results ◦ Serve customers and the organization better ◦ Reasonable time frame and lasting results ◦ Resources available ◦ Necessary or discretionary ◦ Tangible or intangible factors
Discretionary and non-discretionary projects ◦ Necessity of project ◦ Possibly no need to review non-discretionary projects in committee
Purpose ◦ To decide whether to continue the project Objectives for a preliminary investigation 1. Understand the problem 2. Define the project scope and constraints 3. Identify the benefits 4. Estimate the time and costs 5. Report to management Interaction with managers and users
Step 1: Understand the problem ◦ Identify the true nature of the problem and the reason for the systems request ◦ Stated problem may not be the real problem ◦ Clear statement defines the investigation scope
Step 2: Define the project scope and constraints ◦ Project scope Define the range or extent of the project Set project boundaries ◦ Constraints Identify conditions, restrictions, or requirements « Present vs. future « Internal vs. external « Mandatory vs. desirable
Step 3: Perform fact finding ◦ Analyze organization charts ◦ Conduct interviews ◦ Observe operations ◦ Carry out a user survey
Step 5: Estimate time and cost to continue development ◦ Determine what information is needed ◦ Identify the sources of information ◦ Decide whether to use interviews, if so how many, and what time needed ◦ Decide whether to use surveys, if so who to complete it, and what time needed ◦ Estimate the cost of gathering, analyzing, and reporting the information to management
Step 6: Present results and recommendations to management ◦ Final task in the preliminary investigation ◦ Key elements Evaluation of systems request Estimate of costs and benefits Recommendations
Focuses on designing the interactions between end users and computer systems. Designers concentrate on - input/ output methods and - the conversion of data and information between human-readable and machine-readable forms. This is a proto typing process where working models or prototypes of user interface methods are designed and modified with feedback from the end users.
Focuses on -the design of the structure of databases and -files to be used by a proposed information system. Data design frequently produces a data dictionary, which catalogs detailed descriptions of: • The attributes of the entities about which the proposed information system needs to maintain information. • The relationships these entities have with each other. • The specific data elements(databases, files, record, etc..) that need to be maintained for each activity. • The integrity rules that govern how each data
Focuses on the development of software resources, (the programs, procedures) needed by the proposed information system. Process design produces detailed program specifications and procedures needed to meet -the user interface and data design specifications that are developed. -meet the functional control and performance requirements developed in the analysis stage.
Final design must specify what types of hardware resources, network resources, and people resources will be needed. It must specify how such resources will convert data resources into information products. These specifications are the final product of the systems design stage called system specifications.
User interface specifications - Content, format, sequence of user interface products and methods. Database specifications - Content, structure, distribution, maintenance, retention of databases. Software specifications - The required software package of the proposed system
Hardware specifications - The physical and performance characteristics of the equipments and networks. Personnel specifications - Job descriptions of persons who will operate the system.