Systems Analysis and Design Chapter 4 PDF

4 Systems Analysis and Design in a Changing World, Fourth Edition  4 Learning Objectives Describe the activities of the systems analysis life cycle phase Explain th...

4 Systems Analysis and Design in a Changing World, Fourth Edition  4 Learning Objectives Describe the activities of the systems analysis life cycle phase Explain the effect of business process reengineering on activities of the analysis phase Describe the difference between functional and nonfunctional system requirements Identify and understand the different types of users who will be involved in investigating system requirements Systems Analysis and Design in a Changing World, 4th Edition 2  4 Learning Objectives (continued) Describe the kind of information that is required to develop system requirements Determine system requirements through review of documentation, interviews, observation, prototypes, questionnaires, vendor research, and joint application design sessions Discuss the need for validation of system requirements to ensure accuracy and completeness and the use of a structured walkthrough Systems Analysis and Design in a Changing World, 4th Edition 3  4 Overview Analysis phase of SDLC skills needed Fact finding for investigation of system requirements Analyst should learn details of business processes and daily operations Analyst should become as knowledgeable as business domain users to build credibility Analyst brings fresh perspective to problem Modeling of business processes based on system requirements Systems Analysis and Design in a Changing World, 4th Edition 4  4 The Analysis Phase in More Detail Gather information Define system requirements Functional and nonfunctional Prioritize requirements Prototype for feasibility and discovery Generate and evaluate alternatives Review recommendations with management Systems Analysis and Design in a Changing World, 4th Edition 5  4 The Activities of the Analysis Phase (Figure 4-1) Systems Analysis and Design in a Changing World, 4th Edition 6  4 Activities of the Analysis Phase and Their Key Questions (Figure 4-2) Systems Analysis and Design in a Changing World, 4th Edition 7  4 Business Process Reengineering and Analysis Fundamental strategic approach to organizing company Streamlines internal processes to be as efficient and effective as possible Questions basic assumptions for doing business and seeks to find a better way Uses IT as BPR enabler Systems analyst may discover opportunities for process improvement Any project may include components of BPR Systems Analysis and Design in a Changing World, 4th Edition 8  4 System Requirements New system capabilities and constraints Functional requirements Activities system must perform (use cases) Based on procedures and business functions Documented in analysis models Nonfunctional requirements Technical environment or performance objectives Usability, reliability, and security requirements Systems Analysis and Design in a Changing World, 4th Edition 9  4 Stakeholders—The Source of System Requirements People with interest in successful system implementation Three primary groups of stakeholders Users (use system) Clients (pay for and own system) Technical staff (ensure system operation) Every type of stakeholder is identified by analyst Systems Analysis and Design in a Changing World, 4th Edition 10  4 Stakeholders Interested in New System Development (Figure 4-4) Systems Analysis and Design in a Changing World, 4th Edition 11  4 More On Users as Stakeholders Horizontal user roles – information flow across departments Vertical user roles – information needs of clerical staff, middle management, and senior executives Business users perform day-to-day operations Information users need current information Management users need summary information Executive users need strategic information External users may have access to system Systems Analysis and Design in a Changing World, 4th Edition 12  4 Techniques for Information Gathering Analysis phase done to understand business functions and develop system requirements Original structured approach Create model of existing system Derive requirements from existing system model Current approach Identify logical requirements for new system Balance the review of current business functions with new system requirements Systems Analysis and Design in a Changing World, 4th Edition 13  Relationship Between Information 4 Gathering and Model Building (Figure 4-6) Systems Analysis and Design in a Changing World, 4th Edition 14  4 Themes for Information-Gathering Questions (Figure 4-7) Systems Analysis and Design in a Changing World, 4th Edition 15  4 Fact-Finding Methods Review existing reports, forms, and procedure descriptions Interview and discuss processes with users Observe and document business processes Build prototypes Distribute and collect questionnaires Conduct joint application design (JAD) sessions Research vendor solutions Systems Analysis and Design in a Changing World, 4th Edition 16  4 Review Existing Reports, Forms, and Procedure Descriptions Source: External industry-wide professional organizations and trade publications Source: Existing business documents and procedure descriptions within organization Identify business rules, discrepancies, and redundancies Be cautious of outdated material Obtain preliminary understanding of processes Use as guidelines/visual cues to guide interviews Systems Analysis and Design in a Changing World, 4th Edition 17  4 Sample Order Form for RMO (Figure 4-8) Systems Analysis and Design in a Changing World, 4th Edition 18  4 Conduct Interviews and Discussions with Users Effective way to understand business functions and rules Time consuming and resource expensive May require multiple sessions to Meet all users Understand all processing requirements Can meet with individuals or groups of users List of detailed questions prepared Systems Analysis and Design in a Changing World, 4th Edition 19  4 Observe and Document Business Processes Varies from office walkthroughs to performing actual tasks Not necessary to observe all processes at same level of detail May make users nervous, so use common sense Can document workflows with UML activity diagrams Systems Analysis and Design in a Changing World, 4th Edition 20  4 Activity Diagram that Models a Workflow (Figure 4-13) Systems Analysis and Design in a Changing World, 4th Edition 21  4 Build Prototypes Preliminary working model of a larger, more complex system component Discovery, design, evolving prototypes Prototype should be Operative Working model to provide “look and feel” Focused to accomplish single objective Quick Built and modified rapidly with CASE tools Systems Analysis and Design in a Changing World, 4th Edition 22  4 Distribute and Collect Questionnaires Limited and specific information from a large number of stakeholders Preliminary insight into business Not well suited for gathering detailed information Closed-ended questions direct person answering question Open-ended questions encourage discussion and elaboration Systems Analysis and Design in a Changing World, 4th Edition 23  4 Team-Oriented Methods and Techniques These involves the following: Joint application development (JAD) Rapid application development (RAD) Agile methods Systems Analysis and Design in a Changing World, 4th Edition 24  4 Conduct a JAD/Facility (Figure 4-16) Systems Analysis and Design in a Changing World, 4th Edition 25  4 Joint Application Development User Involvement ❑ Users have a vital stake in an information system and they should participate fully ❑ Successful systems must be user-oriented, and users need to be involved ❑ One popular strategy for user involvement is a JAD team approach Systems Analysis and Design in a Changing World, 4th Edition 26  4 Joint Application Development JAD Participants and Roles Systems Analysis and Design in a Changing World, 4th Edition 27  4 Joint Application Development JAD Advantages and Disadvantages: ▪ More expensive and can be cumbersome if the group is too large relative to the size of the project. ▪ Allows key users to participate effectively. ▪ When properly used, JAD can result in a more accurate statement of system requirements, a better understanding of common goals, and a stronger commitment to the success of the new system. Systems Analysis and Design in a Changing World, 4th Edition 28  4 Rapid Application Development Is a team-based technique that speeds up information systems development and produces a functioning information system Relies heavily on prototyping and user involvement Interactive process continues until the system is completely developed and users are satisfied. Based on prototyping and iterative model with no (or less) specific planning. Systems Analysis and Design in a Changing World, 4th Edition 29  4 Rapid Application Development RAD phases and activities: Systems Analysis and Design in a Changing World, 4th Edition 30  4 Rapid Application Development RAD Objectives: To cut development time and expense by involving the users in every phase of systems development. Successful RAD team must have IT resources, skills, and management support. Helps a development team design a system that requires a highly interactive or complex user interface. Systems Analysis and Design in a Changing World, 4th Edition 31  4 Rapid Application Development RAD Advantages and Disadvantages Systems can be developed more quickly with significant cost savings RAD stresses the mechanics of the system itself and does not emphasize the company’s strategic business needs Might allow less time to develop quality, consistency, and design standards Systems Analysis and Design in a Changing World, 4th Edition 32  4 Agile Methods ▪ Attempt to develop a system incrementally ▪ Agilian modeling toolset includes support for many modeling tools ▪ Some agile developers prefer not to use CASE tools at all, and rely instead on whiteboard displays and arrangements of movable sticky notes Systems Analysis and Design in a Changing World, 4th Edition 33  4 Agile Methods Scrum is a rugby term Pigs include the product owner, the facilitator, and the development team; while the chickens include users, other stakeholders,and managers Scrum sessions have specific guidelines that emphasize time blocks, interaction, and teambased activities that result in deliverable software Systems Analysis and Design in a Changing World, 4th Edition 34  4 Agile Methods Agile Method Advantages and Disadvantages Are very flexible and efficient in dealing with change Frequent deliverables constantly validate the project and reduce risk Team members need a high level of technical and interpersonal skills May be subject to significant change in scope Systems Analysis and Design in a Changing World, 4th Edition 35  4 Research Vendor Solutions Many problems have been solved by other companies Positive contributions of vendor solutions Frequently provide new ideas May be state of the art Cheaper and less risky Danger May purchase solution before understanding problem Systems Analysis and Design in a Changing World, 4th Edition 36  4 Useful Techniques in Vendor Research Technical specifications from vendor Demo or trial system References of existing clients On-site visits Printout of screens and reports Systems Analysis and Design in a Changing World, 4th Edition 37  4 The Zachman Framework The Zachman Framework Zachman Framework for Enterprise Architecture Helps managers and users understand the model and assures that overall business goals translate into successful IT projects. Who, What, Where, When, How, and Why? Difference between asking what is being done and what could or should be done Systems Analysis and Design in a Changing World, 4th Edition 38  4 Validating the Requirements Make sure gathered information is correct Structured walkthrough Effective means of implementing quality control early in project Verify and validate system requirements Review of findings from investigation and of models built based on findings Project manager responsible for system quality Systems analyst, project manager are partners Systems Analysis and Design in a Changing World, 4th Edition 39  4 Summary Analysis phase activities Gather information Define system requirements Prioritize requirements Prototype for feasibility and discovery Generate and evaluate alternatives Review recommendations with management BPR and Zachman Framework can help with the analysis phase activities Systems Analysis and Design in a Changing World, 4th Edition 40  4 Summary (continued) Gathering system requirements Functional and nonfunctional Work with various stakeholders (users, clients, technical staff) What kind of information do I need? What are the business processes and operations? How are the business processes performed? What are the information requirements? Systems Analysis and Design in a Changing World, 4th Edition 41  4 Summary (continued) Primary information-gathering techniques Review existing reports, forms, and procedure descriptions Conduct interviews and discussions with users Observe and document business processes Build prototype working models Distribute and collect questionnaires Conduct JAD/RAD/Agile Methods sessions Research vendor solutions Systems Analysis and Design in a Changing World, 4th Edition 42