Information system development p3 investigating

Matakuliah Tahun : M0054 Information System Development : 2012 Topic Investigating System Requirement Rules Read active Bina Nusantara assignments only On time! ask questions Requirements On time! Bina Nusantara PERMISSION TO LEAVE PROHIBITED BEHAVIOUR Investigating System Requirement Points to discuss : • • • • The activity of analysis Phase System Requirement Techniques for Information Gathering Activity Diagrams Bina Nusantara The Activities of the Analysis Phase Figure 4-3 Systems Analysis and Design in a Changing World, 5th Edition Activities of the Analysis Phase and Their Key Questions Figure 4-2 Systems Analysis and Design in a Changing World, 5th Edition System Requirements • • System requirements – specifications that define the new system Functional requirements – – – Activities system must perform (use cases) Based on procedures and business functions Documented in analysis models Systems Analysis and Design in a Changing World, 5th Edition System Requirements (cont) • Nonfunctional requirements – – – – – Technical requirement – hardware and software Performance requirement – workload measures Usability requirement – user interface, workflow Reliability requirement – outages, error detection Security requirement – access & protection Systems Analysis and Design in a Changing World, 5th Edition Models and Modeling • • • • • Analyst describes information system requirements using a collection of models Complex systems require more than one type of model Models represent some aspect of the system being built Process of creating models helps analyst clarify and refine design Models assist communication with system users Systems Analysis and Design in a Changing World, 5th Edition Reasons for Modeling Figure 4-3 Systems Analysis and Design in a Changing World, 5th Edition 10 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, 5th Edition 19 Relationship Between Information Gathering and Model Building Figure 4-8 Systems Analysis and Design in a Changing World, 5th Edition 20 Themes for Information-Gathering Questions Figure 4-9 Systems Analysis and Design in a Changing World, 5th Edition 21 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, 5th Edition 22 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, 5th Edition 23 Sample Order Form for RMO Figure 4-10 Systems Analysis and Design in a Changing World, 5th Edition 24 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, 5th Edition 25 Sample Checklist to Prepare for User Interviews Figure 4-11 Systems Analysis and Design in a Changing World, 5th Edition 26 Sample Agenda for Interview Figure 4-12 Systems Analysis and Design in a Changing World, 5th Edition 27 A Sample Open-Items List Figure 4-13 Systems Analysis and Design in a Changing World, 5th Edition 28 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, 5th Edition 29 Activity Diagrams • • • Workflow – sequence of steps to process a business transaction Activity Diagram – workflow diagram to describe sequence of steps Synchronization bar – symbol to control splitting or merging of a path on an activity diagram • Swimlane – bounded area that contains activities of a single agent Systems Analysis and Design in a Changing World, 5th Edition 30 Activity Diagram Symbols Figure 4-14 Systems Analysis and Design in a Changing World, 5th Edition 31 Activity Diagram that Models a Workflow Figure 4-15 Systems Analysis and Design in a Changing World, 5th Edition 32 Activity Diagram with Concurrent Paths Figure 4-16 Systems Analysis and Design in a Changing World, 5th Edition 33 ... 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... protection Systems Analysis and Design in a Changing World, 5th Edition Models and Modeling • • • • • Analyst describes information system requirements using a collection of models Complex systems... Reasons for Modeling Figure 4-3 Systems Analysis and Design in a Changing World, 5th Edition 10 Types of Models • Different types of models are used in information systems development – Mathematical