12 Building and Maintaining Information Systems

Table 12.1 Microsoft Programs Software for a New Release

Table 12.1 Microsoft Programs Software for a New Release CUSTOMER Customers who purchase Microsoft’s software Microsoft itself, because it must create a basis for new releases and because the software reflects its strategy

Table 12.1 Microsoft Programs Software for a New Release PRODUCT New release of a software product

Table 12.1 Microsoft Programs Software for a New Release BUSINESS PROCESS Major steps: Identify features customers want and features Microsoft wants for strategic reasons Decide which features to include in a release Divide the work among small teams and break each team’s work into three phases Program and test features in each module Performs a daily build to make sure all parts of the product work together Decide which features to delay to subsequent releases Test the entire release Package and distribute the new release Rationale: Produce releases that combine what the customers want and what Microsoft wants to produce Maintain creativity and responsiblity by assigning subprojects to small teams Maintain control and compatibilty by doing a daily build

Table 12.1 Microsoft Programs Software for a New Release PARTICIPANTS Programmers and testers INFORMATION Features to be included in the release Programs Examples for testing Project plan TECHNOLOGY (Not mentioned in the case) Programming languages Debugging techniques Computers that run the programs

Figure 12.1 Costs in design errors detected at different times

Figure 12.2 Links between the four phases of an information system

OPERATION AND MAINTENANCE Table 12.2 Common Issues and Problems in Each Phase of an Information System INITIATION Can we agree on the purposes and goals of the proposed system? Are the requirements unnecessarily elaborate and expensive? DEVELOPMENT Can we assure that the system genuinely solves the user’s problems? Can we assure that users will participate effectively in the design process? IMPLEMENTATION Can we convert effectively and painlessly from the old system to the new system? Can we solve political issues related to changes in power relationships? OPERATION AND MAINTENANCE Can we keep system performance and uptime at acceptable levels? Can we correct bugs and enhance the system to keep it focused on current business problems?

Table 12.3 Differences between Four System Life Cycles TRADITIONAL SYSTEM LIFE CYCLE Issue addressed: Control Summary: Go through a fixed sequence of steps with signoffs after each step and careful documents. PROTOTYPE Issue addressed: Knowledge Summary: Quickly devellop a working model of the system; use the model to gain experience and decide how the final syatem should operate. APPLICATION PACKAGES Issue addressed: Resources and timing Summary: Purchase an existing information system from a vendor; customize the system if necessary. Issue addressed: Responsiveness Summary: Provide tools and support that make it practical for end users to develop their own information systems.

Box 12.1 The capability maturity model Level 1- INITIAL Processes are ad hoc and sometimes chaotic. Because few processes are defined, successful projects often depend on heroic individual effort. Level 2- REPEATABLE Basic project management processes are used to track cost, schedule, and functionality. The discipline exists to repeat previous success with similar projects. Level 3- DEFINED Both management and technical processes are documented and integrated into a standard software process for the organization. Projects use an approved, tailored version of the standard software processes. Level 4- MANAGED Detailed measures of the software process and product quality are collected and that information is used to understand both the product and the process in quantitative terms. Level 5- OPTIMIZING Continuous process improvement is facilitated by quantitative feedback from the process and by doing pilot studies of innovative ideas and technologies.

Figure 12.3 Steps in the development phase of the traditional system life cycle

Figure 12.4 Steps in the implementation phase of the traditional system life cycle

Table 12.4 Steps and Deliverables in the Traditional System Life Cycle INITIATION Feasibility study Degree of user participation- High Key deliverable, plan, or document- Functional specification Key Participants- User representatives, management, and technical staff Project planning Degree of user participation - Medium Key deliverable, plan, or document - Project plan Key Participants deliverable, plan, or document - User representatives, management, and technical staff

Table 12.4 Steps and Deliverables in the Traditional System Life Cycle DEVELOPMENT Detailed requirements analysis Degree of user participation - High Key deliverable, plan, or document - External specification Key Participants- User representatives, management, and technical staff Internal system design Degree of user participation - None Key deliverable, plan, or document - Internal specification Key Participants- Programmers and technical staff Hardware acquisition and installation Key deliverable, plan, or document - Hardware plan Hardware operational Key Participants- Technical staff Programming Key deliverable, plan, or document - Individual programs debugged Key Participants- Programmers Documentation Degree of user participation- Medium Key deliverable, plan, or document - User and programmer documentation Key Participants- Technical staff and users System testing Degree of user participation - Medium Key deliverable, plan, or document - Test plan Completed system test Key Participants- Programmers and users

Table 12.4 Steps and Deliverables in the Traditional System Life Cycle IMPLEMENTATION Implementation planning Degree of user participation - High Key deliverable, plan, or document - Implementation plan Key Participants- Training staff, users, and management Training Key deliverable, plan, or document - Training materials Key Participants- Trainers and users Conversion Key deliverable, plan, or document - System in use Key Participants- Users and project team Acceptance testing Key deliverable, plan, or document - System accepted Postimplementation audit Key deliverable, plan, or document - Audit report Key Participants- Users and management

Table 12.4 Steps and Deliverables in the Traditional System Life Cycle OPERATION AND MAINTENANCE Ongoing operation and support Degree of user participation - Low Key deliverable, plan, or document - Operations manual Key Participants- Technical staff Key deliverable, plan, or document - Usage statistics Key Participants- Technical staff and users Degree of user participation - High Key deliverable, plan, or document - Enhancement requests and bug fix requests Maintenance Degree of user participation - Medium Key deliverable, plan, or document - Maintenance Absorption or termination Degree of user participation - ====== Key deliverable, plan, or document - ====== Key Participants- ======

Table 12.5 System Life Cycle Based on a Prototype INITIATION Users and developers agree to develop a prototype because they need experience with a working model before designing a final system. DEVELOPMENT Working iteratively with users, a prototype is developed and improved. Later, decide whether to complete the prototype or switch to a traditional life cycle. IMPLEMENTATION Accomplish parts of implementation along with development as users work with the prototype system. Dispel skepticism about whether the system will meet users’ needs. OPERATION AND MAINTENANCE May be similar to a traditional life cycle. May require less maintenance because the system fits users’ needs more accurately. May require more maintenance because the system is not constructed as well.

Figure 12.5 Using a prototype approach

Figure 12.6 Creating a data input form (b)

Figure 12.7 Example of a commercial application package

Table 12.6 System Life Cycle for Acquiring an Application Package INITIATION May start with user’s or manager’s recognition of a business problem or with a sales call from a vendor. DEVELOPMENT The vendor develops the software, although the purchase still performs some typical development activities, such as determining detailed requirements. Development may include customization of the software and user documentation. IMPLEMENTATION Implementation starts by deciding exactly how the package will be used. It often relies on the vendor’s staff because they have the greatest knowledge of the system. OPERATION AND MAINTENANCE Operation occurs as it would with a traditional life cycle. Maintenance is different because the vendor maintains the software based on requests from customers and demands of the market.

Box 12.2 Selecting an application package APPLICATION FEATURES completeness quality of reports ease of use documentation TECHNICAL FEATURES use of DBMS transportability expandability VENDOR COMPARISON financial strength management strength committment to product ECONOMIC COMPARISON purchase price maintenance contract consulting charges conversion cost Total weighted score WEIGHT 2.5 1.0 2.3 2.8 0.8 1.2 2.0 1.3 2.6 1.5 0.6 SCORE 9 7 8 9 5 9 5 9 6 3 9 7 8 7 3 2 5 6 4 5 5 9 7 5 6 9 8 4 7 9 7 5 7 7 7 8 5 6 8 5 3 5 WEIGHTED SCORE 22.5 17.3 20.0 9.0 5.0 9.0 11.5 20.7 19.6 8.4 25.2 19.6 22.4 19.6 8.4 1.6 4.0 4.8 4.8 6.0 6.0 18.0 14.0 10.0 7.8 11.7 10.4 10.4 18.2 23.4 14.0 10.0 14.0 10.5 10.5 12.0 3.0 3.6 4.8 11.5 6.9 11.5 155.4 172.9 167.7

Figure 12.8 Vendor responsibilties for application packages

Figure 12.9 A tool for end-user devlopment

Table 12.7 System Life Cycle for End-User Development INITIATION Because the user will develop the information system, a formal functional specification is unnecessary. DEVELOPMENT The user develops the system using tools that do not require a professional level of programming knowledge. Information systems that are critical to the company or have many users require more extensive testing, documentation, and usage procedures. IMPLEMENTATION Implementation is simplified because the developer is the user. OPERATION AND MAINTENANCE End users are responsible. Long-term maintenance and technical quality become larger issues because the end users have other work to do and are not professional programmers.

Figure 12.10 Roles in end-user development

Table 12.8 Common Approaches to Issues in End-User Computing HARDWARE SELECTION AND MAINTENANCE The IS staff selects the types of harware that can be purchased and maintains the hardware. SOFTWARE SELECTION The IS staff selects the the spreadsheet software and other end-user software that can be purchased and used. TRAINING The IS staff provides training for end users on selected hardware and software. DATA AVAILABILITY End users control their own data and share data using LANs. Corporate data are downloaded from central computers. DATA SECURITY Limit access to only the data users need. SYSTEMS ANALYSIS Help end users with systems analysis and design where necessary. Provide help lines and other types of support.

Table 12.9 Advantages and Disadvantages of Four System Life Cycles Traditional system life cycle Prototype Application package End-user development