INFORMATION SYSTEMS X Finalizing Scope functionslevel of automation

INFORMATION SYSTEMS @ X 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 INFO 425: Systems Design

INFORMATION SYSTEMS @ X 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? INFO 425: Systems Design

INFORMATION SYSTEMS @ X Application Deployment Environment § What is the technical environment in which system will be implemented? § Deployment environment consists primarily of: ¨ ¨ ¨ Hardware Networks System software Development methodology and tools § Technical requirements define constraints regarding deployment environment § Organization’s current environment/standards typically drive deployment options INFO 425: Systems Design

INFORMATION SYSTEMS @ X Range of Application Types § Stand-alone applications on mini- and personal computers § Online interactive applications § Distributed applications § Web-based applications INFO 425: Systems Design

INFORMATION SYSTEMS @ X 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 DB 2 § Software components and standards range from Java 2 Enterprise (J 2 EE) to Microsoft. NET § Web servers range from IIS to Apache INFO 425: Systems Design

INFORMATION SYSTEMS @ X 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 INFO 425: Systems Design

INFORMATION SYSTEMS @ X 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 INFO 425: Systems Design

INFORMATION SYSTEMS @ X 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, OS 390, NT ¨ Database management system environment > Oracle, DB 2, SQL Server INFO 425: Systems Design

INFORMATION SYSTEMS @ X Choosing Implementation Alternatives § Many variations on obtaining a system Facilities management solutions ¨ Packaged, turnkey, ERP software systems ¨ Custom software development ¨ In-house development ¨ INFO 425: Systems Design

INFORMATION SYSTEMS @ X Implementation Alternatives ERP SAP People. Soft ASPs Salesforce. com My. SAP. com Off the shelf packages Simply Accounting We build, consultants build or blended approach INFO 425: Systems Design

INFORMATION SYSTEMS @ X Identifying Criteria 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 INFO 425: Systems Design

INFORMATION SYSTEMS @ X Evaluation Framework Weight – importance of criteria vs other criteria Alternatives considered Evaluation Criteria Score INFO 425: Systems Design Score * Weight Total 49 Total 42

INFORMATION SYSTEMS @ X EVALUATION FRAMEWORK (EXPANDED) INFO 425: Systems Design

INFORMATION SYSTEMS @ X 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) INFO 425: Systems Design

INFORMATION SYSTEMS @ X 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. INFO 425: Systems Design

INFORMATION SYSTEMS @ X Functional Requirements § Need to evaluate alternatives based on how well they meet functional requirements. § Use expanded event table INFO 425: Systems Design

INFORMATION SYSTEMS @ X Evaluating Functional Requirements INFO 425: Systems Design

INFORMATION SYSTEMS @ X Evaluating Technical Requirements INFO 425: Systems Design

INFORMATION SYSTEMS @ X Making the Selection u u After rating alternatives, choice can be made Scores are tabulated and compared INFO 425: Systems Design

INFORMATION SYSTEMS @ X Partial Matrix of General Requirements Figure 8 -7 Systems Analysis and Design in a Changing World, 5 th Edition INFO 425: Systems Design 20

INFORMATION SYSTEMS @ X Partial Matrix of Functional Requirements Figure 8 -8 Systems Analysis and Design in a Changing World, 5 th Edition INFO 425: Systems Design 21

INFORMATION SYSTEMS @ X Partial Matrix of Technical Requirements Figure 8 -9 Systems Analysis and Design in a Changing World, 5 th Edition INFO 425: Systems Design 22

INFORMATION SYSTEMS @ X Contracting with Vendors § Generate a Request for Proposal INFO 425: Systems Design

INFORMATION SYSTEMS @ X 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 INFO 425: Systems Design