1. Pertemuan 3 Konsep Dasar Teknologi Informasi
Matakuliah : H0402/PENGELOLAAN SISTEM KOMPUTER
Tahun : 2005
Versi : 1/0
Pertemuan 3 Konsep Dasar Teknologi Informasi

2. Menyebutkan berbagai konsep dasar sistem informasi
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
Menyebutkan berbagai konsep dasar sistem informasi

3. Pendekatan Pembuatan Sistem Kendali Sistem Informasi
Outline Materi
Pengertian Sistem
Proses Bisnis
Sumber Daya Manusia
Pendekatan Pembuatan Sistem
Kendali Sistem Informasi

4. Systems thinking is: a discipline for seeing wholes
THE SYSTEMS VIEW
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)

5. THE SYSTEMS VIEW
What Is a System?
System – a set of interrelated components that must work together to achieve some common purpose

6. THE SYSTEMS VIEW What Is a System?
All components are there … but they don’t work well together!
An Example of Poor Design

7. THE SYSTEMS VIEW
What Is a System?
System – a set of interrelated components that must work together to achieve some common purpose
Information System – the collection of IT, procedures, and people responsible for the capture, movement, management, and distribution of data and information

8. Seven Key System Elements
THE SYSTEMS VIEW
Seven Key System Elements
Boundary
Environment
Inputs
Outputs
Components
Interfaces
Storage
General Structure of a System

9. THE SYSTEMS VIEW
System Component Examples

10. System boundary depends on:
THE SYSTEMS VIEW
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

11. A component of a system is also called a subsystem or module
THE SYSTEMS VIEW
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

12. Goals of hierarchical decomposition:
THE SYSTEMS VIEW
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

13. Functions of an interface:
THE SYSTEMS VIEW
Seven Key System Elements – Interfaces
Interface – point of contact between a system and its environment or between two subsystems
Functions of an interface:
Filtering
Coding/decoding
Error detection and correction
Buffer
Security
Summarizing

14. Interfaces built between two preexisting systems are called bridges
THE SYSTEMS VIEW
Seven Key System Elements – Interfaces
Interfaces built between two preexisting systems are called bridges

15. Possible objective of an interface:
THE SYSTEMS VIEW
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

16. Sales Summary Reporting System

17. Sales Summary Reporting Subsystem

18. Organizations as Systems
THE SYSTEMS VIEW
Organizations as Systems
How does a change in one
affect the others?
Fundamental Components
of an Organization

19. Fundamental principles:
THE SYSTEMS VIEW
Systems Analysis and Design
Systems analysis and design (SA&D) – a process used in developing new information systems based on a systems approach to problem solving
Fundamental principles:
Choose an appropriate scope (boundary selection)
Logical before physical (what before how)

20. Recommended problem-solving steps:
THE SYSTEMS VIEW
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

21. BUSINESS PROCESSES
Business process – a set of work activities and resources

22. evaluate a business process
One way managers can
evaluate a business process
Evaluating Business Processes
(Keen, 1997)

23. BUSINESS PROCESSES
Business Process Redesign
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

24. Six principles for redesigning business processes:
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

25. Six principles for redesigning business processes:
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

26. Business Process Redesign
BUSINESS PROCESSES
Business Process Redesign
How IT Enables New Ways to Work

27. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
The Information Systems Life Cycle
Figure Generic Systems Life Cycle

28. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
The Information Systems Life Cycle
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

29. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
The Information Systems Life Cycle
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

30. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
The Information Systems Life Cycle
Implementation Phase:
Business managers and IS professionals install new system
Data and procedures from old system converted

31. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
Structured Techniques for Life Cycle Development
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

32. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
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

33. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
Procedural-Oriented Techniques
Provides a baseline for the new system
Includes both logical and physical models
Three-Step Modeling Approach

34. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
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
Three-Step Modeling Approach

35. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
Procedural-Oriented Techniques
Conducted by IS specialists
Maps logical requirements to available technology
Three-Step Modeling Approach

36. Boxes
Major modules
Cylinders
Databases
Arrows
Flow of data
Physical Model of a System

37. Tools for the As-Is Model
Must identify existing processes, external participants, other databases or applications, and inputs and outputs
Tools used:
Procedures, policies, manuals, forms, reports
Other documentation
Group interviews

38. Tools for the As-Is Model
Context diagram – positions the system as a whole with regard to other entities and activities with which it interacts
Work process flow diagram – identifies the existing information sources, information sources that are updated, order in which steps occur, and some of the dependencies

39. Tools for the As-Is Model
Context Diagram
for Accounts Payable

40. Work Process Flow Diagram
for Accounts Payable

41. High-level model of a nonexistent new system
Tools for the
Logical To-Be Model
High-level model of a nonexistent new system
Identifies processes and data
Does not identify who does activity, where accomplished, or type of hardware or software
Describes “what” rather than “how”
Most closely associated with data flow diagrams (DFDs)

42. for Accounts Payable System
Tools for the
Logical To-Be Model
Top-Level DFD
for Accounts Payable System

43. for Accounts Payable System
Data Flow
External Entity
Processes
Data Store
Top-Level DFD
for Accounts Payable System

44. Process of creating a DFD:
Tools for the
Logical To-Be Model
Process of creating a DFD:
Identify entities that supply or use system information
Distinguish processes from data they use or produce
Explicate business rules that affect transformation of data to information
Identify logical relationships
Pinpoint duplicate storage and movement of data

45. Lower-level explosion DFD for Process 1.0

46. for Accounts Payable System
Note process
numbering scheme
Second-Level DFD
for Accounts Payable System

47. More logical modeling required after DFDs
Tools for the
Logical To-Be Model
More logical modeling required after DFDs
Need to define system’s data elements and relationships:
Data dictionary/directory (DD/D) used to define data elements
Entity-relationship diagram (ERD) used to define relationships between entities

48. Data Dictionary Sample Entry

49. Tools for the Logical To-Be Model Entity-Relationship Diagram
for Invoice and PO

50. for Logical Data Modeling
Relational Database Terminology
Key Terms
for Logical Data Modeling

51. Tools for physical design represent how:
Tools for Documenting
the Physical To-Be System
Tools for physical design represent how:
processes and data stores partitioned
program control handled
database organized
Tools include:
Program structure chart
Database design
System interface layouts

52. Program Structure Chart

53. Database Design (data relationships)
Relationships for Data Elements in Accounts Payable

54. System Interface Input Layout Form
Input Form Layout for Vendor Invoice

55. Output Report Layout
Check Register Report Layout with Sample Data

56. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
Object-Oriented Techniques
Object approach well suited for client/server applications, graphical interfaces, and multimedia data
Primary advantage is ability to reuse objects programmed by others

57. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
Object-Oriented Techniques
The Promise of Object-Oriented Approaches

58. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
Core Concepts
Object
Encapsulation
Inheritance
Objects communicate with each other through messages
that specify what should be done, not how it should be done
Message Passing

59. PROCESSES AND TECHNIQUES TO DELIVER INFORMATION SYSTEMS
Unified Modeling Language (UML)
For O-O Modeling
UML is standardization for O-O analysis and design modeling techniques and notations
UML diagrams:
Use-case diagrams
Extended relationship use-case diagram
Sequence diagram
Class diagram
Logical modeling begins with use-cases – diagrams and text forms

60. Use Case Diagram
Use Case Diagram

61. Use Case – Text Form
Become Member Use Case

62. INFORMATION SYSTEMS CONTROLS TO MINIMIZE BUSINESS RISKS
Common system security risks:
Human error
Criminal acts
Due to staffing changes and project management deficiencies
Natural disasters
Types of Control Mechanisms
Management policies
Operating procedures
Auditing function

63. INFORMATION SYSTEMS CONTROLS TO MINIMIZE BUSINESS RISKS
Types of Control Mechanisms
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
IS Organization
Backup power supplies
Network access control
Firewall protection
Business Organization
Ensure accurate data entry and handling
Identify procedural errors

64. INFORMATION SYSTEMS CONTROLS TO MINIMIZE BUSINESS RISKS
Types of Control Mechanisms
Pre- and Post-Installation Controls

65. Pendekatan Pembuatan Sistem Kendali Sistem Informasi
Konsep Dasar Teknologi Informasi
Pengertian Sistem
Proses Bisnis
Pendekatan Pembuatan Sistem
Kendali Sistem Informasi