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Finalizing Scope (functions/level of automation). Finalizing scope in terms of functions and level of automation for each function overlaps with and requires information from: Defining target deployment environment Defining implementation alternatives e.g., build vs. buy
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Finalizing Scope (functions/level of automation) • Finalizing scope in terms of functions and level of automation for each function overlaps with and requires information from: • Defining target deployment environment • Defining implementation alternatives • e.g., build vs. buy • General Approach for including/excluding functions: • Functions deemed mandatory are in scope. • Include as many important functions as budget and schedule allow • Desirable features: delay to later ‘release’ of system • Strategic plan: • Often, genesis of a new system is organization’s strategic plan • Functions that align with strategic plan typically get included in scope
Finalizing Scope (functions/level of automation) • Need to revisit feasibility analysis. Now have much more information to work with. • Economic feasibility • What set of functions give us an optimal return on investment? • What set of functions can we afford? • Schedule and resource feasibility • What can be implemented in time available? • What can be implemented given human and other resources? • Technological feasibility • What can be practically implemented given state of technology and organizations knowledge and experience? • Operational, organizational, and cultural feasibility • What can our organization handle/accept? • How much change is required?
Application Deployment Environment • What is the technical environment in which system will be implemented? • Deployment environment consists primarily of: • Hardware • Networks • System software • Development software • Development methodology and tools • Technical requirements define constraints regarding deployment environment • Organization’s current environment/standards typically drive deployment options
Range of Application Types • Stand-alone applications on mini- and personal computers • Online interactive applications • Distributed applications • Web-based applications
Hardware, System Software, and Networks • Computers range from handheld to super computers • Operating systems range from Windows to Unix • Database management systems range from Oracle to SQL Server to IBM DB2 • Software components and standards range from Java 2 Enterprise (J2EE) to Microsoft .NET • Web servers range from IIS to Apache
Deployment Environment Characteristics to Consider • Compatibility with technical requirements: • Volume of transactions, location of users, etc. • Compatibility among hardware and system software • Required interfaces to external systems • Conformity with IT strategic plan and architecture plans • Cost and schedule
Development Tools • Development environment – programming languages, CASE tools, and other software used to develop application software • Java and Visual Studio .NET are examples • Application deployment environment decisions limit development tool choices • Operating system environment • Database management system (DBMS) • Distributed software standard
Development and System Software Environments • Consists of standards and tools used in an organization to develop systems • Important considerations • Language environment and expertise • Java, C, etc, • Existing CASE tools and methodologies • RUP and Rose, Information Engineering • Required interfaces to other systems • Operating system environment • Unix, Linux, OS390, NT • Database management system environment • Oracle, DB2, SQL Server
Choosing Implementation Alternatives • Many variations on obtaining a system • Facilities management solutions • Packaged, turnkey, ERP software systems • Custom software development • In-house development
Implementation Alternatives ASPs Salesforce. com MySAP.com ERP SAP PeopleSoft Off the shelf packages Simply Accounting We build, consultants build or blended approach
IdentifyingCriteria for Selection • Comparisons difficult • Different proposed systems have strengths in different areas • Need a consistent framework for comparison of alternatives • Criteria • Weights • Scores • Three areas to consider • General requirements • Functional requirements • Technical requirements
Evaluation Framework Weight – importance of criteria vs other criteria Alternatives considered Evaluation Criteria Total 49 Total 42 Score * Weight Score
General Requirements • General requirements include considerations that are important but not directly associated with the computer system itself. • Related to feasibility assessment – alternative must be feasible to be chosen • General requirements examples: • Performance record of the provider • Level of technical support from the provider • Warranties and support services (from outside vendor) • Availability of experienced staff • Development cost • Expected value of benefits • Length of time (schedule) until deployment • Requirements for internal expertise • Organizational impacts (retraining, skill levels)
Technical Requirements • Constraints under which system must operate • Defined by technical requirements identified during information gathering • Categories: • Performance (response time/throughput, etc) • Security and Control • User interface (ease of use, etc.) • Service (number/location of users to be supported) • Operating environment • etc.
Functional Requirements • Need to evaluate alternatives based on how well they meet functional requirements. • Use expanded event table
Making the Selection • After rating alternatives, choice can be made • Scores are tabulated and compared
Systems Analysis and Design in a Changing World, 5th Edition Partial Matrix of General Requirements Figure 8-7
Systems Analysis and Design in a Changing World, 5th Edition Partial Matrix of Functional Requirements Figure 8-8
Systems Analysis and Design in a Changing World, 5th Edition Partial Matrix of Technical Requirements Figure 8-9
Contracting with Vendors • Generate a Request for Proposal
Presenting Results and Making Decisions • Compile, organize, and present the alternatives and critical issues in an easy-to-understand but complete manner • Final choice generally made by executive steering committee • Format of documentation and presentation style varies with organization