Information system development p3 investigating

The Activities of the Analysis Phase Systems Analysis and Design in a Changing World, 5th Edition 5 Figure 4-3... Activities of the Analysis Phase and Their Key Questions Systems Analysi

Topic 3 Investigating System Requirement

Matakuliah : M0054 Information System Development

Bina Nusantara

Rules

Bina Nusantara

Requirements

Investigating System Requirement

The Activities of the Analysis Phase

Systems Analysis and Design in a Changing World, 5th Edition 5

Figure 4-3

Activities of the Analysis Phase

and Their Key Questions

Systems Analysis and Design in a Changing World, 5th Edition 6

Figure 4-2

Systems Analysis and Design in a Changing World, 5th Edition 7

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 8

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 9

Reasons for Modeling

Systems Analysis and Design in a Changing World, 5th Edition 10

Figure 4-3

Types of Models

• Different types of models are used in information systems development

– Mathematical – formulas that describe technical aspects of the system

– Descriptive – narrative memos, reports, or lists that describe aspects of the system

– Graphical – diagrams and schematic representations of some aspect of the system

Systems Analysis and Design in a Changing World, 5th Edition 11

Some Descriptive Models

Systems Analysis and Design in a Changing World, 5th Edition 12

Figure 4-4

Overview of Models Used

in Analysis and Design

• Analysis activities named “define system requirements”

– Logical models– Provide detail without regard to specific technology

• Design models

– Physical models – Provide technical details– Extend logical models

Systems Analysis and Design in a Changing World, 5th Edition 13

Models Created

During Analysis

Systems Analysis and Design in a Changing World, 5th Edition 14

Figure 4-5

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, 5th Edition 15

Stakeholders Interested

in New System Development

Systems Analysis and Design in a Changing World, 5th Edition 16

Figure 4-6

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, 5th Edition 17

RMO Stakeholders

Systems Analysis and Design in a Changing World, 5th Edition 18

Figure 4-7

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

Relationship Between Information Gathering and Model Building

Systems Analysis and Design in a Changing World, 5th Edition 20

Figure 4-8

Themes for Information-Gathering Questions

Systems Analysis and Design in a Changing World, 5th Edition 21

Figure 4-9

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

Systems Analysis and Design in a Changing World, 5th Edition 24

Figure 4-10

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

Systems Analysis and Design in a Changing World, 5th Edition 26

Figure 4-11

Sample Agenda for

Interview

Systems Analysis and Design in a Changing World, 5th Edition 27

Figure 4-12

A Sample Open-Items List

Systems Analysis and Design in a Changing World, 5th Edition 28

Figure 4-13

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

Systems Analysis and Design in a Changing World, 5th Edition 31

Figure 4-14

Activity Diagram with Concurrent Paths

Systems Analysis and Design in a Changing World, 5th Edition 33

Figure 4-16