Information Systems Development Chapter 11 Information Systems Development

Chapter Objectives To understand the phases of new major information systems development. To appreciate the strengths and weaknesses of the formal systems development life cycle approach. To understand alternative ways to acquire or develop information systems. To appreciate how effective project management can reduce risks in systems development efforts.

Suggestion to Minimize Risk of I/S Development Align I/S Plans with organizational strategy. Define the problem or opportunity clearly. Assess (and reassess) the project feasibility. Apply appropriate project management techniques and systems development tools. Assign the right people. Ensure appropriate controls are enforced.

Roles in I/S Development User Business Analyst Systems Analyst Programmer Database Administrator Infrastructure analyst Change management analyst Project Manager

System Development Process Systems Development Life Cycle Project Planning Analysis Generation and evaluation of alternatives Designing Implementation Maintenance and operation of the system

Structured vs. Object Oriented Development Structured Development Evolved during the 1970s and 1980s. Employ a variety of diagrams and documentation. ERDs, DFDs, and Structured Programming. Require large amounts of time and documentation. Dissatisfaction with structured techniques lead to object oriented techniques.

Object Oriented Techniques Object oriented programming languages facilitated the use of object oriented development techniques. An object is a representation of a thing. Objects interact with other objects and with people. Unified Modeling Language (UML) provides standards for object oriented development.

SDLC Step 1 Step 1: Project Planning Define the goals and objectives. Why should the information system be built. System request from outside I/S may generate idea. Feasibility assessment is performed to see if the idea is: Technically feasible Economically feasible Critical Success Factors Activities and measures that have to be done in order to succeed.

SDLC Step 2 Analysis Define Information Requirements Understand the existing system. Identify improvement opportunities. Develop the requirements specifications for the new system. Techniques to determine information requirements Interviews Document sampling Joint application design Questionnaires Direct observation Identify the desired output. Identify the data needed to produce the desired output.

SDLC Step 3 Generation and Evaluation of Alternatives Mistake to implement first workable solution. Should generate several feasible alternatives. Reason for shortfall in generating alternatives. Communication gap between end user and systems specialist. Systems specialist may also present a limited set of alternatives based on what they are familiar with.

SDLC Step 3 Assessing a Systems Feasibility Technical assessment How risky are the technical aspects of the alternative. Organizational assessment Looks at stakeholder support to see how much support there will be after completion. Economic assessment Cost –benefit analysis of each alternative. Total cost of ownership Attempts to consider all applicable costs and allocates them over a reasonable life.

SDLC Step 3 Tangible and Intangible Measures Tangible costs of each alternative are easy to measure costs. Software licenses, computing hardware, training costs. Intangible costs of each alternative are hard to measure costs. Disruption to operations during switch over, length of time for employees to learn new system. Tangible benefits easy to measure benefits associated with each alternative. Intangible benefits hard to measure benefits associated with each alternative.

SDLC Step 4 Designing the chosen alternative. Architecture Networks, hardware, software, security. User Interface Input screens, output, navigation. Data storage Files, databases Application logic and procedures. Programs and directions on how to use the system.

SDLC Step 4 Testing is an important part of the design phase. Unit testing Ensures each module is working correctly . Program testing Ensures that the modules work together. System testing Evaluates the entire system. Integration testing Ensures system interacts with others systems without generating errors.

SDLC Step 5 Implementation Involves all the steps required to move from the existing system to the new one. Four general approaches to converting to a new system. Parallel conversion, involves running both the old and new system for a period of time. Pilot conversion, new system is implemented in a subset of the organization. Phased conversion, implementation of new system is done in phases. Direct cutover, the plug is pulled on the old system and conversion to the new one happens immediately.

SDLC Step 6 Maintenance and Operation Maintenance involves upgrading the system as required. Maintenance is an on-going process. Patches System security Backup and recovery plans

CASE Tools To ensure that easy to maintain systems are produced numerous software packages or CASE tools have been created. Computer-Aided Systems Engineering (CASE) tools. CASE tools focus on either the analysis phase or the design and implementation phase.

Alternative Techniques End User Development The ultimate end user of the system is also the developer. User will have a strong sense of ownership. May avoid documentation and have inadequate testing. Scalability and integration problems may arise. Rapid Application Development (RAD) Tools allow for fast development. Phased development. Application service provider.

Operational Vulnerabilities Increases with the reliance on I/S Vulnerabilities include: I/S that is rigid and inflexible. Lacks functionality. Lack error detection

Effective Project Management Many I/S projects come in late and over budget. Business priorities and practices may change during the development. External factors might force changes. Apply effective project management techniques. Break projects into smaller more measurable tasks. Create and monitor detailed project schedules. Ensure that required resources are available and committed.