CIS 321—IS Analysis & Design Chapter 4: Analysis— Investigating System Requirements

2 Overview A reminder—the ______ consists of five phases: Planning Analysis Design Implementation Maintenance Two key activities (skills) involved with analysis: Investigate the system requirements* Model the business processes to meet the requirements** Investigation Become an expert about the current/proposed system *Covered in this chapter **Covered in Chapter 5

3 Activities of the Analysis Phase Gather information Define system requirements Prioritize system requirements Prototype for feasibility and __________ Generate and evaluate alternatives Review recommendations with management

4 Gather (All) Information About the existing business process/information system Interview users/stakeholders Observe users Become deeply involved About the proposed business process/information system Interview users of similar systems About the technical issues of the existing/proposed system ___________ with other systems Software packages that may meet requirements

5 Define System Requirements Types of requirements Functional—what functions need to be performed __________—how to perform the required functions Two types of models Detailed logical Performed during analysis, w/o reference to technology Detailed __________ Performed during design, w/ reference to technology How to model Create, refine, cross-validate with other models Specific models depend on development methodology

6 Prioritize Requirements Categorize system functions Essential Desirable Resources are limited Each requirement must be justified Without prioritization, scope _______ can occur

7 Prototype Two reasons for prototyping in the analysis phase Verify the plan can meet existing requirements Problem domain (user view) Technology domain (system view) ___________ new requirements Problem domain (user view) Technology domain (system view)

8 Generate and Evaluate Alternatives Possible alternatives for system development In-house development Third party development Packaged software Also known as make vs. _____

9 Review Recommendations w/ Management Keep management informed throughout the analysis phase Decisions Should the project continue? (go-no go) If so, which alternative should be selected? What is the revised budget and schedule?

10 Business Process Reengineering Different philosophies about change If it ain’t broke, don’t fix it _____________ improvement (many small improvements) BPR (major changes) Customer ____________ management (CRM) Keep detailed information about customers to serve them better What if BPR costs jobs? If your company doesn’t make major improvements, your competitors will and you will go out of business entirely If possible, go beyond the obvious requirements

11 System Requirements Definition All of the capabilities and constraints that the new system must meet Two types of system requirements Functional (functions the system must perform) Nonfunctional (how the system must function) Technical (What operating system? Wireless network?) Performance (Response time? Number of users?) Usability (Types of menus? Legal disclaimers?) Reliability (Required uptime? Procedures for downtime?) Security (Who has access?)

12 Stakeholders—The Source Definition Those who have an interest in the successful implementation of the system All stakeholders must be included in analysis Types of stakeholders Users Horizontal—across departments Vertical—business, information, management, executive, external _______ Person or group providing the funding for the project Technical staff Can the technical staff support the technical requirements?

13 Old vs. New Systems In the past… the existing system was completely documented before the new system was studied Today… the analyst begins with the new system requirements (to save time) the existing system is studied only to discover business needs

14 Themes for Questions The goal: build a _______ model of the new system Three major questions must be answered in detail What are the business processes? How is the business process performed? What information is required? Be effective and efficient in your analysis

15 Information Gathering Methods Review existing documentation (external / internal) Conduct interviews with users (checklist, p. 130) prepare, conduct, follow up Observe and document business processes use activity diagrams (part of UML) to document workflow Build prototypes desired characteristics: operative, focused, quick Distribute and collect questionnaires (limited use) Conduct JAD or GSS sessions Research vendor solutions (but be careful)

16 Validating Requirements Developing a system is like constructing a building Structured walkthrough—a review of all the findings during analysis What and when? All the models developed Who? Developers and stakeholders How? preparation execution follow-up