590 likes | 762 Views
B. Information Technology (IS) CISB434: Decision Support Systems. Chapter 9: System Development & Acquisition. Learning Objectives. Describe the basic concepts of systems development Discuss the major steps in developing decision support system (DSS) management support system (MSS).
E N D
B. Information Technology (IS)CISB434: Decision Support Systems Chapter 9: System Development & Acquisition
Learning Objectives • Describe the basic concepts of systems development • Discuss the major steps in developing • decision support system (DSS) • management support system (MSS)
Learning Objectives • List the major MSS application develop-ment options • along with the benefits and limitations • describe the four phases of the system development life cycle: • planning • analysis • development • implementation
Learning Objectives • Discuss various MSS application out-sourcing options • including the use of an application service provider (ASP) • utility computing
Learning Objectives • Describe prototyping methodology • explain why MSSs are typically developed using these methods • describe the factors that lead to success or failure • discuss the learning process that occurs during development • discuss the concept of end-user computing
Learning Objectives • Give some major MSS software pack-ages and MSS application suites • examine the criteria for selection • Describe various methods for connect-ing an MSS application to back-end systems and databases • discuss the value and technical foundation of Web Services in integrated applications
Learning Objectives • Describe the criteria used in selecting an outsourcing vendor and package
System Development & Acquisition Basic Concepts of Systems Development
MSS DevelopmentIntroduction • Types of Support Systems • Infrastructure • Data Warehouses and Business Intelligence • Knowledge Management Systems • Enterprise Information Systems • Portals
MSS DevelopmentIntroduction • Types of Support Systems • Specific applications • Tools and tool kits • Platforms
MSS DevelopmentThe Landscape & Framework • Step 1: • Planning, identifying, and justifying MSS • Step 2: • Creating an MSS architecture • MSS architecture • A plan for organizing the underlying infrastruc-ture and applications of the MSS project
MSS DevelopmentThe Landscape & Framework • Step 3: • Selecting a development option • Build the system in house • Have a vendor build a custom-made system • Buy an existing application and install it, with or without modifications, by yourself or through a vendor
MSS DevelopmentThe Landscape & Framework • Step 3: • Selecting a development option • Lease standard software from an ASP, utility computing, or set up a software-as-a-service arrangement • Enter into a partnership or an alliance that will enable the company to use someone else's application • Use a combination of these approaches
MSS DevelopmentThe Landscape & Framework • Step 4: • Installing, testing, connecting, and deploy-ing MSS applications • Step 5: • Operations, maintenance, and updating
MSS DevelopmentThe Landscape & Framework • Managing the development process • The development process can be fairly complex and must be managed properly • For medium to large applications, a project team is usually created to manage the process and the vendors • Project management software
System Development & Acquisition Development Options
MSS DevelopmentDevelopment Options • In-house development (in-sourcing) • Outsourcing • Buy from off the shelf • Lease from vendor
MSS DevelopmentDevelopment Options • In-house development - Insourcing • Development options for in-house development • Building from scratch • Building from components • Integrating applications • Need to have the expertise/ skills in house • Good for specialized application
MSS Developmentin-house development-Methods used • Methods used in in-house development • System Development Life Cycle (SDLC) • A systematic process for the effective construc-tion of large information systems
MSS Developmentin-house development-Methods used • Rapid application development (RAD) • A development methodology that adjusts a system development life-cycle • so that parts of the system can be develo-ped quickly • enabling users to obtain some functionality as soon as possible • Includes methods of phased development • e.g. prototyping, and throwaway prototyping
MSS Developmentin-house development-Methods used • Prototyping • A strategy in which a scaled-down system or portion of a system • is constructed in a short time, tested, and improved • in several iterations
MSS DevelopmentDevelopment Options • Buying applications - cost, maintenance/support provided… • Leasing applications • Lease from an outsourcer and then install it on the company’s premises • Lease from an ASP that hosts the application at its data center
MSS DevelopmentDevelopment Options • Methods used in in-house development • Software-as-a-service (SaaS) • Software that is rented instead of sold
MSS DevelopmentDevelopment Options • Factors driving the switch to software-as-a-service: • Reducing the risks involved in acquiring new software • Influencing product and service quality via an ongoing relationship with vendors
MSS DevelopmentDevelopment Options • Factors driving the switch to software-as-a-service: • Changing usage commitments as business circumstances change • Preparing financially justifiable business cases • More accurately predicting ongoing expen-ses
Development Options • If custom software is required, the alternatives of insourcing and outsourcing should be compared. • A key consideration is the availability of in-house resources.
Development Options • If do not have the resources to build in-house, need to consider buy off the shelf (package) or lease from vendor: • if the application is sufficiently popular that packages and/or ASPs exist for it • their total cost of ownership (TOC) should be compared for the firm’s planning horizon. • The cost of using a package should include any component integration costs. The cost of using an ASP should include estimated price increases.
System Development & Acquisition MSS Application Outsourcing Options
MSS DevelopmentOutsourcing Options • Application Service Providers (ASP) • A software vendor that offers leased soft-ware applications to organizations
MSS DevelopmentOutsourcing Options • Utility (on-demand) computing • Unlimited computing power and storage capacity that, • like electricity, water, telephone services, • can be obtained on demand, used, and reallocated for any application, • and billed on a pay-per-use basis
System Development & Acquisition Prototyping
PrototypingAdvantages • Short development time • Short user reaction time • i.e. feedback from user • Improved user understanding of the system • its information needs, and its capabilities • Low cost
PrototypingLimitations • Gains obtained from cautiously stepping through each of the system’s lifecycle stages might be lost including: • A thorough understanding of the informa-tion system’s benefits and costs • A detailed description of the business’s information needs
PrototypingLimitations • Gains obtained from cautiously stepping through each of the system’s lifecycle stages might be lost including: • An easy-to-maintain information system design • A well-tested information system • Well-prepared users
PrototypingDevelopment Process • Users and managers, as well as an exe-cutive sponsor, must be involved • The analysis, design, and prototype im-plementation phases are iteratively per-formed • until a small prototype is sufficiently deve-loped
PrototypingDevelopment Process • The final implementation takes place • Simultaneously, further iterations occur • as other subsystems or capabilities are added to the deployed system • until a fairly stable, comprehensive system evolves
PrototypingCollaboration in Prototyping • The interaction of user, developer, and technology is extremely important in the prototyping process
PrototypingEvaluation in Prototyping • Iterative design • A systematic process for system develop-ment that is used in MSS • produce a first version of MSS • then revise it and produce the second design version and so on • is an iterative design
PrototypingImplementing Prototyping • Target small, tactical applications that show quick results • Use software components • Make application deployment iterative and open to customization • Use commodity hardware • Use object technology • including tools such as Java
PrototypingImplementing Prototyping • Break major projects into manageable, deliverable chunks • Use packaged applications whenever justifiable • Consider IT service providers as well as utility and grid computing • Use Web services, if possible
PrototypingSuccesses Factors • Users and managers should be invol-ved in every phase and iteration • Learning should be explicitly integrated into the design process • Prototyping should essentially bypass the formal information requirement defi-nition in the SDLC
PrototypingSuccesses Factors • A key criterion associated with proto-typing is the short interval between iterations • The initial prototype must be low cost
PrototypingFailures • No prelaunch objectives or metrics • Too many major projects were conduc-ted simultaneously • The CEO set budgets and deadlines before the project team was involved • The budget and deadlines were not rea-listic
PrototypingFailures • There was no insider presence on the data warehouse project team • An overburdened project manager was involved • The availability of source data was un-confirmed at the outset
PrototypingFailures • No user demand for sophisticated data analysis was considered • No routine meetings of executive spon-sors and the project manager • Business managers were not initially involved
PrototypingLessons Learned from Failure • Most critical success factors for develo-ping a data warehouse • executive sponsorship • partnership of the IT staff and end users • Unclear understanding of the business objectives and how they are measured