1. Pertemuan - 15 Matakuliah: M0304/Corporate Information System Management Tahun: 2008

2. Fakultas Ilmu Komputer Modul-15-2 Konsep Dasar Sistem I NFORMASI

3. Fakultas Ilmu Komputer Modul-15-3 Pandangan Sistem Systems thinking is: – a discipline for seeing wholes – a framework for seeing interrelationships rather than things – an antidote to feeling of helplessness when dealing with complexity Peter Senge (1990)

4. Fakultas Ilmu Komputer Modul-15-4 System – a set of interrelated components that must work together to achieve some common purpose Pandangan Sistem What Is a System?

5. Fakultas Ilmu Komputer Modul-15-5 T HE S YSTEMS V IEW All components are there … but they don’t work well together! Figure 15.1 Contoh Rancangan jelek What Is a System?

6. Fakultas Ilmu Komputer Modul-15-6 System – a set of interrelated components that must work together to achieve some common purpose T HE S YSTEMS V IEW What Is a System? Information System – the collection of IT, procedures, and people responsible for the capture, movement, management, and distribution of data and information

7. Fakultas Ilmu Komputer Modul-15-7 Seven Key System Elements T HE S YSTEMS V IEW 1.Boundary 2.Environment 3.Inputs 4.Outputs 5.Components 6.Interfaces 7.Storage Figure 15.2 General Structure of a System

8. Fakultas Ilmu Komputer Modul-15-8 Figure 15.3 System Component Examples

9. Fakultas Ilmu Komputer Modul-15-9 Seven Key System Elements – System Boundary System boundary depends on:  What can be controlled  What scope is manageable within a given time period  The impact of a boundary change T HE S YSTEMS V IEW

10. Fakultas Ilmu Komputer Modul-15-10 Seven Key System Elements – Component Decomposition A component of a system is also called a subsystem or module Hierarchical decomposition – the process of breaking down a system into successive levels of subsystems, each showing more detail T HE S YSTEMS V IEW

11. Fakultas Ilmu Komputer Modul-15-11 Seven Key System Elements – Component Decomposition Goals of hierarchical decomposition:  To cope with system complexity  To analyze or change part of the system  To design and build each subsystem at different times  To direct the attention of a target audience  To allow system components to operate more independently T HE S YSTEMS V IEW

12. Fakultas Ilmu Komputer Modul-15-12 Seven Key System Elements – Interfaces Functions of an interface: – Filtering – Coding/decoding – Error detection and correction – Buffer – Security – Summarizing Interface – point of contact between a system and its environment or between two subsystems T HE S YSTEMS V IEW

13. Fakultas Ilmu Komputer Modul-15-13 Seven Key System Elements – Interfaces Interfaces built between two preexisting systems are called bridges T HE S YSTEMS V IEW

14. Fakultas Ilmu Komputer Modul-15-14 Seven Key System Elements – Interfaces Possible objective of an interface: – System decoupling – changing two system components so that modifying one does not necessarily require modifying the other T HE S YSTEMS V IEW

15. Fakultas Ilmu Komputer Modul-15-15 Figure 15.4 Sales Summary Reporting System

16. Fakultas Ilmu Komputer Modul-15-16 Figure 9.4 Sales Summary Reporting Subsystem

17. Fakultas Ilmu Komputer Modul-15-17 Organizations as Systems Figure 15.5 Fundamental Components of an Organization How does a change in one affect the others? T HE S YSTEMS V IEW

18. Fakultas Ilmu Komputer Modul-15-18 Systems Analysis and Design Fundamental principles: – Choose an appropriate scope (boundary selection) – Logical before physical (what before how) Systems analysis and design (SA&D) – a process used in developing new information systems based on a systems approach to problem solving T HE S YSTEMS V IEW

19. Fakultas Ilmu Komputer Modul-15-19 Systems Analysis and Design Recommended problem-solving steps: Problem (or system) is a set of problems that must be broken down into smaller, more manageable problems Single solution is not always obvious to all – alternatives should be generated and considered Understanding of problem changes, so reassess commitment to solution at various stages T HE S YSTEMS V IEW

20. Fakultas Ilmu Komputer Modul-15-20 Business process – a set of work activities and resources B USINESS P ROCESSES

21. Fakultas Ilmu Komputer Modul-15-21 One way managers can evaluate a business process Figure 15.6 Evaluating Business Processes (Keen, 1997)

22. Fakultas Ilmu Komputer Modul-15-22 Business process reengineering (BPR) – radical business redesign initiatives that attempt to achieve dramatic improvements in business processes by questioning the assumptions, or business rules, that underlie the organization’s structures and procedures B USINESS P ROCESSES Business Process Redesign

23. Fakultas Ilmu Komputer Modul-15-23 Page 363 B USINESS P ROCESSES Business Process Redesign Six principles for redesigning business processes:  Organize business processes around outcomes, not tasks  Assign those who use the output to perform the process  Integrate information processing into the work that produces the information

24. Fakultas Ilmu Komputer Modul-15-24 B USINESS P ROCESSES Business Process Redesign Six principles for redesigning business processes:  Create a virtual enterprise by treating geographically distributed resources as though they were centralized  Link parallel activities instead of integrating their results  Have the people who do the work make all the decisions, and let controls built into the system monitor the process

25. Fakultas Ilmu Komputer Modul-15-25 B USINESS P ROCESSES Business Process Redesign Figure 15.7 How IT Enables New Ways to Work

26. Fakultas Ilmu Komputer Modul-15-26 P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS The Information Systems Life Cycle Figure 15.8 Generic Systems Life Cycle

27. Fakultas Ilmu Komputer Modul-15-27 Definition Phase: End user and systems analysts conduct analysis of current system and business processes Analysis is: – Process-oriented – Data-oriented Business case generated and solution chosen P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS The Information Systems Life Cycle

28. Fakultas Ilmu Komputer Modul-15-28 P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS Construction Phase: System designed, built, and tested System logically described, then physically Technology chosen Programs, inputs, and outputs designed Software programmed and tested User acceptance testing conducted The Information Systems Life Cycle

29. Fakultas Ilmu Komputer Modul-15-29 P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS Page 364 Implementation Phase: Business managers and IS professionals install new system Data and procedures from old system converted The Information Systems Life Cycle

30. Fakultas Ilmu Komputer Modul-15-30 System development methodology – framework consisting of guidelines, tools, and techniques for managing skills to address the business issue Consists of processes, tools, techniques for developing systems Prescribe who participates, roles, development stages and decision points, and formats for documentation P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS Structured Techniques for Life Cycle Development

31. Fakultas Ilmu Komputer Modul-15-31 Structured Techniques for Life Cycle Development Structured techniques – tools to document system needs, requirements, functional features, dependencies, and design decisions Procedural-oriented – Most common – Include data-oriented, sequential, process-oriented activities Object-oriented – Newer approach – Often used for GUIs and multimedia applications P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS

32. Fakultas Ilmu Komputer Modul-15-32 Procedural-Oriented Techniques Provides a baseline for the new system Includes both logical and physical models Figure 15.9 Three-Step Modeling Approach P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS

33. Fakultas Ilmu Komputer Modul-15-33 Procedural-Oriented Techniques Critical appraisal of existing work processes to: Identify major subprocesses, entities, and interactions Separate processing from data flow Capture relationships between data elements Determine entities and processes within scope Figure 15.9 Three-Step Modeling Approach P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS

34. Fakultas Ilmu Komputer Modul-15-34 Procedural-Oriented Techniques Conducted by IS specialists Maps logical requirements to available technology Figure15.9 Three-Step Modeling Approach P ROCESSES AND T ECHNIQUES TO D ELIVER I NFORMATION S YSTEMS

35. Fakultas Ilmu Komputer Modul-15-35 I NFORMATION S YSTEMS C ONTROLS TO M INIMIZE B USINESS R ISKS Common system security risks: – Human error – Criminal acts – Due to staffing changes and project management deficiencies – Natural disasters

36. Fakultas Ilmu Komputer Modul-15-36 I NFORMATION S YSTEMS CONTROLS TO M INIMIZE B USINESS R ISKS Management policies Operating procedures Auditing function Types of Control Mechanisms

37. Fakultas Ilmu Komputer Modul-15-37 I NFORMATION S YSTEMS CONTROLS TO M INIMIZE B USINESS R ISKS Controls built into the information system itself: – To maintain data integrity – Allow only authorized access – Ensure proper system operation – Protect against malfunctions, power outages, and disasters Types of Control Mechanisms

38. Fakultas Ilmu Komputer Modul-15-38 I NFORMATION S YSTEMS C ONTROLS TO M INIMIZE B USINESS R ISKS IS Organization – Backup power supplies – Network access control – Firewall protection Business Organization – Ensure accurate data entry and handling – Identify procedural errors Types of Control Mechanisms

39. Fakultas Ilmu Komputer Modul-15-39 Types of Control Mechanisms Figure 15.14 Pre- and Post-Installation Controls INFORMATION SYSTEMS CONTROLS TO MINIMIZE BUSINESS RISKS

40. Fakultas Ilmu Komputer Modul-15-40 end