systems methodologies and modeling ( overview ) · dosen: yudi priyadi, m.t. fakultas ekonomi dan...

Program Studi: Manajemen Bisnis Telekomunikasi & InformatikaMata Kuliah: Systems Analysis and Design

Oleh: Yudi Priyadi

Systems Methodologies and Modeling

( OVERVIEW )

Telkom University

2 Creating the great business leaders

Program Studi:MANAJEMEN BISNIS TELEKOMUNIKASI & INFORMATIKA

Dosen:Yudi Priyadi, M.T.

Fakultas Ekonomi dan BisnisSchool Economic and Business

GRADING

• TASK-1 (individual & group) : 20 %

• MID TEST : 30 %

• TASK-2 (individual & group) : 20 %

• FINAL TEST : 30 %

REFERENCE:

• Kenneth E. Kendall, Julie E. Kendall (2008), Systems Analysis and

Design, 9th Edition, Prentice Hall

• Yourdon.com

• Pressman, Roger (2010) Software Engineering: A Practitioner's Approach,

7th Edition, McGraw-Hill Higher Education

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Systems, Roles, and Development Methodologies

SOURCE: Systems Analysis and Design, 9eKendall & Kendall, Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall

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Understand the need for systems analysis and design in organizations.

Realize what the many roles of the systems analyst are.

Comprehend the fundamentals of three development methodologies:

SDLC

The agile approach

Object-oriented systems analysis and design

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Learning Objectives

Kendall & KendallCopyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall

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Fuels business and can be the critical factor in determining the success or failure of a business

Needs to be managed correctly

Managing computer-generated information differs from handling manually produced data

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Information—A Key Resource


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Fundamentals of different kinds of information systems

Roles of systems analysts

Phases in the systems development life cycle as they relate to Human-Computer Interaction (HCI) factors

Open Source Software

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Major Topics


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Installing a system without proper planning leads to great user dissatisfaction and frequently causes the system to fall into disuse

Lends structure to the analysis and design of information systems

A series of processes systematically undertaken to improve a business through the use of computerized information systems

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Need for Systems Analysis and Design


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The analyst must be able to work with people of all descriptions and be experienced in working with computers

Three primary roles:

Consultant

Supporting expert

Agent of change

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Roles of the Systems Analyst


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Problem solver

Communicator

Strong personal and professional ethics

Self-disciplined and self-motivated

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Qualities of the Systems Analyst


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The systems development life cycle is a phased approach to solving business problems

Developed through the use of a specific cycle of analyst and user activities

Each phase has unique user activities

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Systems Development Life Cycle (SDLC)


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The Seven Phases of the Systems Development Life Cycle (Figure 1.1)


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Activity:

Interviewing user management

Summarizing the knowledge obtained

Estimating the scope of the project

Documenting the results

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Identifying Problems, Opportunities, and objectives

Output:

Feasibility report containing problem definition and objective summaries from which management can make a decision on whether to proceed with the proposed project


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Activity:

Interviewing

Sampling and investing hard data

Questionnaires

Observe the decision maker’s behavior and environment

Prototyping

Learn the who, what, where, when, how, and why of the current system

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Determining Human Information Requirements Output:

The analyst understands how users accomplish their work when interacting with a computer

Begin to know how to make the new system more useful and usable

Know the business functions

Have complete information on the: People Goals Data Procedure involved


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Activity:

Create data flow, activity, or sequence diagrams

Complete the data dictionary

Analyze the structured decisions made

Prepare and present the system proposal

Output:

Recommendation on what, if anything, should be done

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Analyzing System Needs


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Activity:

Design procedures for data entry

Design the human-computer interface

Design system controls

Design database and/or files

Design backup procedures

Output

Model of the actual system

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Designing the Recommended System


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Activity:

System analyst works with programmers to develop any original software

Works with users to develop effective documentation

Programmers design, code, and remove syntactical errors from computer programs

Document software with help files, procedure manuals, and Web sites with Frequently Asked Questions

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Developing and Documenting Software

Output:

Computer programs

System documentation

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Activity: Test the information system

System maintenance

Maintenance documentation

Output: Problems, if any

Updated programs

Documentation

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Testing and Maintaining the System


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Activity: Train users

Analyst plans smooth conversion from old system to new system

Review and evaluate system

Output: Trained personnel

Installed system

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Implementing and Evaluating the System


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FIGURE 1.6The repository concept.


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Based on:

Values

Principles

Core practices

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The Agile Approach Communication

Simplicity

Feedback

Courage

Agile Values

Resources are adjusted to ensure successful project completion

Time

Cost

Quality

Scope

Four Agile Resources

Exploration

Planning

Iterations to the first release

Productionizing

Maintenance

Five Stages of Agile Development

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Agile Project Development Process (Figure 1.5)


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Alternate approach to the structured approach of the SDLC that is intended to facilitate the development of systems that change rapidly in response to dynamic business environments

Analysis is performed on a small part of the system followed by design and implementation

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Object-Oriented (O-O) Systems Analysis and Design

The cycle repeats with analysis, design, and implementation of the next part and this repeats until the project is complete

Examines the objects of a system

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Define the use case model:

Use case diagram

Use case scenarios

Create UML diagrams

Develop class diagrams

Draw statechart diagrams

Modify the UML diagrams

Develop and document the system

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Unified Modeling Language (UML) Phases


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Choose either:

SDLC

Agile

Object-oriented methodologies

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Choosing a Method


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Systems have been developed and documented using SLDC

It is important to document each step

Upper level management feels more comfortable or safe using SDLC

There are adequate resources and time to complete the full SDLC

Communication of how new systems work is important

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When to Use SDLC


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There is a project champion of agile methods in the organization

Applications need to be developed quickly in response to a dynamic environment

A rescue takes place (the system failed and there is no time to figure out what went wrong)

The customer is satisfied with incremental improvements

Executives and analysts agree with the principles of agile methodologies

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When to Use Agile


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The problems modeled lend themselves to classes

An organization supports the UML learning

Systems can be added gradually, one subsystem at a time

Reuse of previously written software is a possibility

It is acceptable to tackle the difficult problems first

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When to Use Object-Oriented


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An alternative of traditional software development where proprietary code is hidden from the users

Open source software is free to distribute, share, and modify

Characterized as a philosophy rather than simply the process of creating new software

Examples: Linux Operating System, Apache Web Server, Mozilla Firefox

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Open Source Software


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Ad hoc

Standardized

Organized

Commercial

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Four Types of Open Source Communities:


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General structure

Environment

Goals

Methods

User community

Licensing

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Six Key Dimensions that Differentiate Open Source Communities


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Rapidity with which new software can be developed and tested

Faster to have a committed group of experts develop, test, and debug code

This fosters creativity

Have many good minds work with innovative applications

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Reasons for Participating in Open Source Communities

Potential to reduce development costs

Bolster their self-image

Contribute something worthwhile to the software development community


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Contributions to the open community and differentiation from the open community are for the following reasons:

Cost

Managing resources

Time it takes to bring a new product to the market

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Open Source Contribution and Differentiation


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Curiosity about software benefits

Achieve collective design

Incorporate open source software design into: Proprietary products

Processes

Knowledge

IT artifacts

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Reasons for Analyst Participation in the Open Source Community


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Through a process of collective design the IT artifact is imbued with

Community and organizational structures

Knowledge

Practices

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Collective Design


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Information is a key resource

Integration of traditional systems with new technologies

Roles and qualities of the systems analyst

The systems development life cycle

CASE tools

Agile systems development

Object-oriented systems development

Open source systems

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Summary


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Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall

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Understanding and Modeling

Organizational Systems

SOURCE: Systems Analysis and Design, 9eKendall & Kendall, Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall

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Understand that organizations and their members are systems and that analysts need to take a systems perspective.

Depict systems graphically using context-level data flow diagrams, and entity-relationship models, use cases, and use case scenarios.

Recognize that different levels of management require different systems.

Comprehend that organizational culture impacts the design of information systems.

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Learning Objectives


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Organizations as systems

Depicting systems graphically

Data flow diagram

Entity-relationship model

Use case modeling

Levels of management

Organizational culture

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Major Topics

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Conceptualized as systems designed to accomplish predetermined goals and objectives

Composed of smaller, interrelated systems serving specialized functions

Specialized functions are reintegrated to form an effective organizational whole

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Organizations as Systems

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All systems and subsystems are interrelated and interdependent

All systems process inputs from their environments

All systems are contained by boundaries separating them from their environments

System feedback for planning and control

An ideal system self-corrects or self-regulates itself.

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Interrelatedness and Independence of Systems

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System Outputs Serve as Feedback that Compares Performance with Goals (Figure 2.1)


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A virtual organization has parts of the organization in different physical locations

Computer networks and communications technology are used to bring virtual teams together to work on projects

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Virtual Organizations and Virtual Teams

Possibility of reducing costs of physical facilities

More rapid response to customer needs

Helping virtual employees to fulfill their familial obligations to children or aging parents

Benefits of Virtual Organizations and Teams

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Allows system analyst to understand businesses before they begin their tasks

It is important that members of subsystems realize that they are interrelated with other subsystems

Problems occur when each manager thinks that his/her department is the most important

Bigger problems may occur when that manager rises through the ranks

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Taking a Systems Perspective


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Taking a Systems Perspective (Figure 2.2)

Outputs from one

department serve as

inputs for another such

that subsystems are

interrelated.


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Perspective of FunctionalManagers (Figure 2.3)


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Enterprise Systems or Enterprise Resource Planning (ERP) describes an integrated organizational information system

Software that helps the flow of information between the functional areas within the organization

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Enterprise Resource Planning


ERP can affect every aspect of the organization, including:

Design of employees’ work

Skills required for job competency

Strategic positioning of the company

ERP and the Organization

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Many issues must be overcome for the ERP installation is to be declared a success:

User acceptance

Integration with legacy systems and the supply chain

Upgrading functionality (and complexity) of ERP modules

Reorganizing work life of users and decision makers

Expanded reach across several organizations

Strategic repositioning of the company

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Issues to be Overcome for ERP Success


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Context-level data flow diagrams

Entity-relationship model

Use case modeling

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Depicting Systems Graphically


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Focus is on the data flowing into and out of the system and the processing of the data

Shows the scope of the system:

What is to be included in the system

The external entities are outside the scope of the system

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Context-Level Data Flow Diagrams


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The Basic Symbols of a Data Flow Diagram (Figure 2.4)


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Airline Reservation System (Figure 2.5)

A context-level data

flow diagram

for an airline

reservation systemKendall & KendallCopyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall

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Focus is on the entities and their relationships within the organizational system

Another way to show the scope of a system

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Entity-Relationship Model

Relationships show how the entities are connected

Three types of relationships:

One-to-one

One-to-many

Many-to-many

Relationships

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Entity-Relationship Example (Figure 2.7)

An entity-

relationship

diagram

showing a

many-to-one

relationship


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Examples of Different Types of Relationships in E-R Diagrams (Figure 2.8)


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Fundamental entity

Associative entity

Attributive entity

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Entities

Three Different Types of Entities Used in E-R Diagrams (Figure 2.9)


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List the entities in the organization

Choose key entities to narrow the scope of the problem

Identify what the primary entity should be

Confirm the results of the above through data gathering

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Creating Entity-Relationship Diagrams


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A More Complete E-R Diagram Showing Data Attributes of the Entities (Figure 2.12 )


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Describes what a system does without describing how the system does >>> A logical model of the system

Use case is a view of the system requirements

Analyst works with business experts to develop requirements

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Use Case Modeling


Actor Refers to a particular role of a user of the system

Similar to external entities; they exist outside of the system

Use case symbols An oval indicating the task of the use case

Connecting lines Arrows and lines used to diagram behavioral relationships

Use Case Diagram

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Divided into two groups

Primary actors: Supply data or receive information from the system

Provide details on what the use case should do

Supporting actors: Help to keep the system running or provide help

The people who run the help desk, the analysts, programmers, and so on

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Actor

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An actor that initiates an event

The event that triggers a use case

The use case that performs the actions triggered by the event

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A Use Case Always Provides Three Things


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Behavioral relationships

Communicates

Used to connect an actor to a use case

Includes

Describes the situation in which a use case contains behavior that is common to more than one use case

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Use Case Relations

Extends

Describes the situation in which one use case possesses the behavior that allows the new case to handle a variation or exception from the basic use case

Generalizes

Implies that one thing is more typical than the other thing

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Four Types Of Behavioral Relationships And The Lines Used To Diagram Each(Figure 2.13)


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Some components of use case diagrams showing actors, use cases, and relationships for a student enrollment example (Figure 2.14)


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System scope defines its boundaries:

What is in or outside the system

Project has a budget that helps to define scope

Project has a start and an end time

Actors are always outside of scope

Communication lines are the boundaries and define the scope

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Scope


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Review the business specifications and identify the actors involved

May use agile stories

Identify the high-level events and develop the primary use cases that describe those events and how the actors initiate them

Review each primary use case to determine the possible variations of flow through the use case

The context-level data flow diagram could act as a starting point for creating a use case

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Developing Use Case Diagrams


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A Use Case Diagram Representing a System

Used to Plan a Conference (Figure 2.15 )


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The description of the use case

Three main areas:

Use case identifiers and initiators

Steps performed

Conditions, assumptions, and questions

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Developing the Use Case Scenarios


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A Use Case Scenario Is Divided into Three Sections (Figure 2.16)

Use case name: Register for Conference UniqueID: Conf RG 003

Area: Conference Planning

Actor(s): Participant

Stakeholder Conference Sponsor, Conference Speakers

Level Blue

Description: Allow conference participant to register online for the conference using a secure Web site.

Triggering Event: Participant uses Conference Registration Web site, enters userID and password, and clicks the logon button.

Trigger type: External Temporal

Steps Performed (Main Path) Information for Steps

1. Participant logs in using the secure Web server userID, Password

More steps included here…

12. Successful Registration Confirmation Web page is sent to the participant Registration Record Confirmation Number

Preconditions: Participant has already registered and has created a user account.

Postconditions: Participant has successfully registered for the conference.

Assumptions: Participant has a browser and a valid userID and password.

Success Guarantee: Participant has registered for the conference and is enrolled in all selected sessions.

Minimum Guarantee: Participant was able to logon.

Requirements Met: Allow conference participants to be able to register for the conference using a secure Web site.

Outstanding Issues: How should a rejected credit card be handled?

Priority: High

Risk: Medium


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Has a name and a unique ID

Include application area

List actors

Include stakeholders

Include the level

Has a brief description of the use case

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Use Case Header Area


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Use case levels describe how global or detailed the use case description is:

White (like clouds): enterprise level

Kite: business unit or department level

Blue (sea level): user goals

Indigo (or fish): functional or subfunctional

Black (or clam): most detailed

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Use Case Levels


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Extensions or exceptions to the main use case

Number with an integer, decimal point, integer

Steps that may or may not always be used

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Alternative Scenarios


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Preconditions—need to be met before use case can be performed

Postconditions or the state of the system after the use case has finished

Assumptions

Minimal guarantee

Success guarantee

Outstanding issues

Optional priority and risk

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Use Case Footer Area


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Use agile stories, problem definition objectives, user requirements, or a features list

Ask about the tasks that must be done

Determine if there are any iterative or looping actions

The use case ends when the customer goal is complete

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Four Steps Used to Create Use Cases


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Identify all the actors in the problem domain

Actions that need to be completed are also clearly shown on the use case diagram

The use case scenario is also worthwhile

Simplicity and lack of technical detail

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Why Use Case Diagrams Are Helpful


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The Main Reasons for Writing Use Cases Are Their Effectiveness in Communicating with Users and Their Capturing of User Stories (Figure 2.18)


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Management in Organizations Exists on Three Horizontal Levels: Operational Control, Managerial Planning and Control, and Strategic Management (Figure 2.19)


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Make decisions using predetermined rules that have predictable outcomes

Oversee the operating details of the organization

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Operations Control


Make short-term planning and control decisions about resources and organizational objectives

Decisions may be partly operational and partly strategic

Managerial Planning and Control

Look outward from the organization to the future

Make decisions that will guide middle and operations managers

Work in highly uncertain decision-making environment

Define the organization as a whole

Strategic Management

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Organizational fundamentals

Organizations as systems

Levels of management


Graphical representation of systems

DFD

ERD

Use case diagrams and scenarios

2-80

Summary Levels of managerial control

Operational

Middle management

Strategic


systems methodologies and modeling ( overview ) · dosen: yudi priyadi, m.t. fakultas ekonomi dan...

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