Systems Investigation and Analysis

3/26/00

Overview of Systems Development

Participants in Systems Development (Figure 12.1)

Stakeholders
Individuals who either themselves or through the organization are beneficiaries of the systems development effort.
Users
Individuals who interact with the system regularly.
Systems Analyst
Professional who specializes in analyzing and designing business systems.
Programmer
Individual responsible for modifying or developing programs to satisfy user requirements.

Team Leaders for Different Systems Development Projects (Table 12.1)

Typical Reasons to Initiate a Systems Development Project (Figure 12.2)

Planning (Figure 12.3)

Information Systems Planning
The translation of strategic and organizational goals into systems development initiatives.
Creative Analysis
The investigation of new approaches to existing problems.
Critical Analysis
The unbiased and careful questioning of whether system elements are related in the most effective or efficient ways.

Steps of IS Planning (Figure 12.4)

Establishing Objectives for Systems Development

Systems Development and the Internet

Cost of change as a function of phase of project

Systems Development Life Cycles (Figure 12.6)

Systems Investigation
Problems and opportunities are identified
Systems Analysis
Existing systems and work processes are studied
Systems Design
Defines how the information system will do what it must do to solve the problem.
Implementation
System components are assembled and the new or modified system is placed into operation.
Maintenance
Ensures the system operates and is modified to keep up with business changes.

Traditional SDLC (Table 12.2)Developers proceed with each stage. Management review at end of each stage. Maximum management control
In short, only works on problems already solved at least once.

Prototyping: The Iterative Life Cycle (Figure 12.7)

Operational Prototype
Accesses real data files, edits input data, makes necessary computations and comparisons, and produces real output.
Nonoperational Prototype
A mockup or model that includes output and input specifications and formats.
Rapid Application Development (RAD)
Employs tools, techniques, and methodologies designed to speed application development, automates source code generation, and facilitates user involvement in design and development activities Problem: often results in developer burnout
Joint Application Development (JAD)
Involves group meetings in which users, stakeholders, and IS professionals work together to analyze existing systems, proposed solutions, and define requirements for a new or modified system.

General Model of Prototyping (Figure 12.8)

Advantages and Disadvantages of Prototyping (Table 12.3) Equivalent to doing system without planning. Lots of (small) wasted efforts. Can get locked into first mistaken effort. Lack of documentation, fancy features.

Advantages and Disadvantages of Rapid Application Development (RAD) (Table 12.4) Biggest is developer burn-out. Also, requires more user/manager involvement than other approaches.

RAD and prototyping tend to be very similar. Working prototypes are developed while Trad. SDLC is still brainstorming features. Versions developed this way tend to be weak on security, robustness.

Versions tend to actually get developed this way. Working prototypes can be developed with (much) less than 1/1000 th effort of full Trad. SDLC effort.

End-User Systems Development Life Cycle Any systems development project in which the primary effort is undertaken by a combination of business managers and users.

Factors Affecting Systems Development Success (Figure 12.9)Risk increases with magnitude of change--small changes involve low risk; large changes involve large risk.

Managing Change
Requires the ability to recognize existing or potential problems and deal with them before they become a serious threat to the success of the new or modified system.

Factors Affecting Systems Development Success (Table 12.5)

Solving wrong problem
Poor problem definition
Poor communication
Project too ambitious
Lack of management support
Lack of involvement

Factors Affecting Systems Development Success

Gantt Chart (Figure 12.10)

Selected Project Management Software Packages (Table 12.6) Project has taken over the market

Use of Computer-Aided Software Engineering (CASE) Tools

Computer-Aided Software Engineering (CASE)
Tools that automate many of the tasks required in a system development effort and enforces adherence to the SDLC.
Upper CASE Tools
Tools that focus on activities associated with the early stages of systems development.
Lower CASE Tools
Tools that focus on the later implementation stage of systems development.
Integrated-CASE (I-CASE) Tools
Tools that provide links between upper- and lower-CASE packages, allowing lower-CASE packages to generate program code from upper-CASE package generated designs.

Selected I-CASE Tools (Table 12.7)

Advantages and Disadvantages of CASE Tools (Table 12.8)

Advantages: better system, better documentationDisadvantages of CASE Tools Hard to use

Systems Investigation (Figure 12.11)

Feasibility Analysis (Table 12.9)

Net Present Value (Table 12.10)

The preferred approach for ranking competing projects and determining economic feasibility. Discounts future cash flows by discount rate.

Example: Invest 10M, save 2M 1st year, 3M 2nd year, 2M 3rd year, 2M 4th year, 4M 5th year. At 15%, what is the NPV?

The Systems Investigation Report

Table of Contents for the Systems Analysis Report (Figure 12.12)

External and Internal Sources of Data (Figure 12.13)

Data Collection (Figure 12.14)

Data Analysis

Data Analysis
Manipulating the collected data so that it is usable for the development team members who are participating in systems analysis.
Data Modeling
A commonly accepted approach to modeling organizational objects and associations that employ both text and graphics.
Activity Modeling
A method to describe related objects, associations, and activities.
Data Flow Diagram
A diagram that models objects, associations, and activities by describing how data can flow between and around them.

Diagrams (Figure 12.15)

Application Flowchart (Figure 12.16)

Application Flowcharts
Charts that show relationships among applications or systems.
Grid Charts
A table that shows relationships among the various aspects of a systems development effort.

Grid Charts (Figure 12.17)

Requirements Analysis (Figure 12.18)

Screen Layouts (Figure 12.19) Type in Word what screens of final system will look like

The Systems Analysis Report

Typical Table of Contents for a Report on an Existing System (Figure 12.20)