Information Systems Overview (COIS 20024) Lecture: Week 10 Developing Information Systems...

Information Systems OverviewInformation Systems Overview(COIS 20024)(COIS 20024)

Lecture: Week 10

Developing Information Systems

(Information Systems Development & Management)

24-SEP-2001

Daniel Pun, School of Computing & Information Systems, CQU, Australia 2

Week 10: ResourcesWeek 10: ResourcesWeek 10: ResourcesWeek 10: Resources

Study Guide Module 10: Developing Information Systems

Textbook Chapter 10: Developing E-Business Solutions

Resource Materials

Reading 10-1 & 10-2

24-SEP-2001


ObjectivesObjectivesObjectivesObjectives

Identify & describe the stages of the traditional IS development life cycle

Discuss what is involved in SA & SD Explain how prototyping changes the

traditional IS development activities Describe how CASE tools are used in systems

development Explain why & how users should be involved

in IS analysis & implementation

24-SEP-2001


Objectives Objectives (cont’d)(cont’d)Objectives Objectives (cont’d)(cont’d)

Discuss what is involved in IS implementation Discuss the evaluation factors that should be

considered in evaluating the acquisition of H/W, S/W, and IS services

Identify some of the challenges involved in the implementation process for managing technological change

24-SEP-2001


ObjectivesObjectivesObjectivesObjectives






24-SEP-2001


Designthe

Solution

Designthe

Solution

Definethe

Problem

Definethe

Problem

DevelopAlternativeSolutions

DevelopAlternativeSolutions

Selectthe

Solution

Selectthe

Solution

Implementthe

Solution

Implementthe

Solution

Mo

nit

or

and

E

valu

ate

Res

ult

s

Systems Approach to Problem SolvingSystems Approach to Problem SolvingSystems Approach to Problem SolvingSystems Approach to Problem Solving

24-SEP-2001


The systems approach views a business process as a system that has 5 components: input, process, output, feedback & control. The systems approach to problem solving uses the systems orientation to conceptualize the nature of the problem. Under the systems orientation, all elements of a problem interact with one another. Consequently, the systems approach considers each "step" to influence & provide feedback on every other step.

Systems Approach to Problem Solving Systems Approach to Problem Solving (cont’d)(cont’d)Systems Approach to Problem Solving Systems Approach to Problem Solving (cont’d)(cont’d)

24-SEP-2001


The traditional IS development cycle is based upon the stages in the systems approach to problem solving, where each step is interdependent on the previous step.

Using the systems approach to develop IS solutions can be viewed as a multistep process called the information systems development cycle, also known as the systems development life cycle (SDLC). The SDLC is composed of five steps.

Traditional IS Development Life CycleTraditional IS Development Life CycleTraditional IS Development Life CycleTraditional IS Development Life Cycle

24-SEP-2001


Systems ImplementationProduct:

Operational System

Systems ImplementationProduct:

Operational System

Systems InvestigationProduct:

Feasibility Study

Systems InvestigationProduct:

Feasibility Study

Systems AnalysisProduct:

Functional Requirements

Systems AnalysisProduct:

Functional Requirements

Systems DesignProduct:

System Specifications

Systems DesignProduct:

System Specifications

Systems MaintenanceProduct:

Improved System

Systems MaintenanceProduct:

Improved System

Understand theBusinessProblem orOpportunity

Develop anInformationSystemSolution

Implementthe InformationSystemSolution

Traditional IS Development Life Cycle Traditional IS Development Life Cycle (cont’d)(cont’d)Traditional IS Development Life Cycle Traditional IS Development Life Cycle (cont’d)(cont’d)

24-SEP-2001


Systems Investigation: This stage may begin with a formal information systems planning process to help sort out choices from many opportunities. Typically, due to the expense associated with IS development this stage includes a cost/benefit analysis as part of a feasibility study.


24-SEP-2001


Systems Analysis: This stage includes an analysis of the info needs of end users, the organisational environment, and any system currently used to develop the functional requirements of a new system.

Systems Design: This stage develops specifications for the H/W, S/W, people, network, & data resources of the system. The info products the system is expected to produce are also designated.


24-SEP-2001


Systems Implementation: Here the organisation develops or acquires the H/W & S/W needed to implement the system design. Testing of the system & training of people to operate & use the system are also part of this stage. Finally, the organisation converts to the new system.

Systems Maintenance: In this stage, management uses a postimplementation review process to monitor, evaluate, & modify the system as needed.


24-SEP-2001


When using the SDLC: All the activities involved are highly

related and interdependent Several developmental activities can

occur at the same time Different parts of a development project

can be at different stages of the development cycle

May recycle back at any time to repeat previous activities in order to modify & improve a system being developed


24-SEP-2001








24-SEP-2001


Systems Analysis (SA) describes what a system should do to meet the information needs of users

Systems Design (SD) specifies how the system will accomplish this objective

SA & SDSA & SDSA & SDSA & SD

24-SEP-2001


SA is an in-depth study of end user info needs, which produces functional requirements that are used as the basis for the design of a new IS. SA traditionally involves a detailed study of:

The info needs of the company & the end users The activities, resources, & products of any

present IS being used The IS capabilities required to meet the info

needs of end users, and those of other E-business stakeholders that may use the system

Systems Analysis (SA)Systems Analysis (SA)Systems Analysis (SA)Systems Analysis (SA)

24-SEP-2001


KeyAreas ofSystemsAnalysis

OrganizationalOrganizational

FunctionalRequirements

FunctionalRequirements

PresentSystemPresentSystem

SA SA (cont’d)(cont’d)SA SA (cont’d)(cont’d)

24-SEP-2001


Organisational analysis involves evaluating the organisational & environmental systems & subsystems involved in any situation. SA traditionally involves a detailed study of the organisations:

Environment Management structure People Business activities Environmental systems it deals with Current IS


24-SEP-2001


Before designing a new system, a detailed analysis of the current system (manual or automated) must be completed. An analysis of the present system involves analyzing activities, resources, and the products. We must analyse how the present system uses:

H/W, S/W, people resources to convert data resources into info products, such as reports & displays

Document how the info activities of input, processing, output, storage, & control are being accomplished


24-SEP-2001


Functional Requirements Analysis: This step of SA is one of the most difficult. Steps involve:

Working as a team with IS analysts & end users to determine specific business info needs

Determining the info processing capabilities required for each system activity (input, processing, output, storage, & control) to meet the info needs. Goal is to identify What should be done NOT how to do it

Developing functional requirements (info requirements that are not tied to the h/w, s/w, network, data, & people resources that end users presently use or might use in the new system)


24-SEP-2001


SD consists of design activities, which produce systems specifications satisfying the functional requirements developed in the SA stage. These specifications are used as the basis for: S/W development H/W acquisition System testing Other activities of the implementation

stage

Systems Design (SD)Systems Design (SD)Systems Design (SD)Systems Design (SD)

24-SEP-2001


DataDesignData

Design

UserInterfaceDesign

UserInterfaceDesign

ProcessDesign

ProcessDesign

Screen, Form, Reportand Dialog Design

Data ElementStructure Design

Program andProcedure Design

SD SD (cont’d)(cont’d)SD SD (cont’d)(cont’d)

24-SEP-2001


SD can be viewed as the design of three major products, or deliverables, that should result from the design stage. These activities include: User interface design Data design Process design

SD SD (cont’d)(cont’d)SD SD (cont’d)(cont’d)

24-SEP-2001








24-SEP-2001


Prototyping is the rapid development & testing of working models, or prototypes, of new applications in an interactive, iterative process involving both IS specialists & business professionals.

Prototyping makes the development process faster & easier for IS specialists & business professionals.

PrototypingPrototypingPrototypingPrototyping

24-SEP-2001


Prototyping makes the development process faster & easier, especially for projects where end user requirements are hard to define. Thus, prototyping is sometimes called rapid application design (RAD).

Prototyping has also opened up the application development process to end-users because it simplifies & accelerates systems design. These developments are changing the roles of end users & IS specialists in systems development.

Prototyping Prototyping (cont’d)(cont’d)Prototyping Prototyping (cont’d)(cont’d)

24-SEP-2001


Typically, large E-business systems still require using the traditional systems development approach, but parts of such systems can frequently be prototyped.

A prototype of a business application needed by an end user is developed quickly using a variety of application development software tools. The prototype system is then repeatedly refined until it is acceptable.

Prototyping is an iterative, interactive process that combines steps of the traditional systems development cycle, & allows the rapid development & testing of a working model.

Prototyping Prototyping (cont’d)(cont’d)Prototyping Prototyping (cont’d)(cont’d)

24-SEP-2001


Use and Maintainthe Accepted

System

Use and Maintainthe Accepted

System

Identify an EndUser's Information

Requirements

Identify an EndUser's Information

Requirements

DevelopInformation System

Prototypes

DevelopInformation System

Prototypes

Revise the Prototypesto Better Meet EndUser Requirements

Revise the Prototypesto Better Meet EndUser Requirements

PrototypingCycle

MaintenanceCycle

Prototyping ProcessPrototyping ProcessPrototyping ProcessPrototyping Process

24-SEP-2001


Identify Requirements: End users identify their info needs & assess the feasibility of several alternative info system solutions.

Develop Prototype: End users and/or systems analysts use application development packages to interactively design & test prototypes of IS components that meet end user info needs.

Revise Prototype: During this stage, the IS prototypes are used, evaluated, & modified repeatedly until end users find them acceptable.

Use & Maintain: The accepted system can be modified easily since most system documentation is stored on disk.

Prototyping Process Prototyping Process (cont’d)(cont’d)Prototyping Process Prototyping Process (cont’d)(cont’d)

24-SEP-2001








24-SEP-2001


The traditional systems development life cycle (SDLC) process has often been too inflexible, time-consuming, & expensive for many organizations to utilise. To overcome some of the shortfalls of the SDLC, Computer-Aided Systems Engineering (CASE) has emerged. CASE involves using software packages called CASE tools, to perform many of the activities of the SDLC.

CASE ToolsCASE ToolsCASE ToolsCASE Tools

24-SEP-2001


CASE software packages are available to help do:

Business planning Project management User interface design Database design Software development

CASE Tools CASE Tools (cont’d)(cont’d)CASE Tools CASE Tools (cont’d)(cont’d)

24-SEP-2001


Many CASE packages -- help to automate the use of graphics tools

such as flowcharts and data flow diagrams. provide tools for the front end of the

systems development life cycle (planning, analysis, & design) & the back end (implementation & maintenance).

include a system repository component that expands the role of the data dictionary as a catalog of data definitions.


24-SEP-2001


A system repository provides systems analysts with computer-aided data descriptions & other cataloguing facilities, beginning with their systems planning & systems analysis activities, & continuing through the design, implementation, & maintenance of the system. Thus, the repository has become a database for all the details of a system generated with other systems development tools.


24-SEP-2001


Integrated CASE tools (I-CASE) can assist all of the stages of systems development.

Some CASE tools support -- Joint application design (JAD): a group of

systems analysts, programmers, & end users can jointly & interactively design new applications

Backward engineering: allow systems analysts to inspect the logic of a program code for old applications & convert it automatically into more efficient programs that significantly improve system effectiveness.


24-SEP-2001








24-SEP-2001


Direct end user participation in systems development projects before a system is implemented is especially important to reducing the potential for end user resistance. This involvement helps ensure that end users “assume ownership” of a system, and that its design meets their needs.

End User InvolvementEnd User InvolvementEnd User InvolvementEnd User Involvement

24-SEP-2001






24-SEP-2001


ConversionConversionSystemDocu-

mentation

SystemDocu-

mentation

End UserTrainingEnd UserTraining

Developmentand

Modification

Developmentand

ModificationAcquisitionAcquisition

ImplementationActivities

ImplementationActivities

SystemTestingSystemTesting

IS ImplementationIS ImplementationIS ImplementationIS Implementation

24-SEP-2001


The implementation process involves developing the IS into an operational system for end users. Key activities include:

Acquisition of Hardware, Software, & Services: Some very large organisations purchase proprietary H/W & S/W solutions. An increasing number of companies can purchase off-the-shelf H/W & S/W from original equipment manufacturers or resellers.

IS Implementation IS Implementation (cont’d)(cont’d)IS Implementation IS Implementation (cont’d)(cont’d)

24-SEP-2001


Software Development or Modification: Some companies write their own software in-house. Even for those firms that buy software off-the-shelf, modification is often necessary (indeed, the flexibility to modify software is built in to most application programs).

System Testing: Involves testing website or application performance. It may involve such activities as testing & debugging S/W & testing new H/W.

End User Training: This is a vital activity. Provisions & resources for training end users on the new system must be identified & allocated.


24-SEP-2001


System Documentation: How to use & maintain the system must be provided in the form of manuals and, increasingly, online help. In addition, a detailed record of the system’s design is essential for future problem diagnostics or making changes. This effort is simplified through the use of CASE tools.

Conversion: This involves the actual logistics of switching to the new system.


24-SEP-2001






24-SEP-2001


In today’s E-Business environment, acquisition of hardware, software, and IS services is an important part of E-application development. How should companies make such acquisition choices? What process should they use for selecting vendors?

EvaluatingEvaluatingEvaluatingEvaluating

24-SEP-2001


Hardware Hardware Evaluation Evaluation FactorsFactors

Performance Cost Reliability Compatibility Technology Connectivity Scalability Support Software

Software Software Evaluation Evaluation

FactorsFactors Quality Flexibility Security Connectivity Language Documentation Hardware Efficiency

Evaluation Factors: H/W & S/WEvaluation Factors: H/W & S/WEvaluation Factors: H/W & S/WEvaluation Factors: H/W & S/W

24-SEP-2001


When acquiring IS services, other evaluation factors need to be considered. These include:

Past Performance: Referrals from past customers is essential.

Business Position: Is the vendor financially strong, with good industry prospects?

Service & Capabilities: What kind of services can they offer? What kind of equipment do they have available?

Accessibility: Does the vendor provide local or regional support?

Maintenance and Guarantees: Will they maintain their product? Are there warranties?

Evaluation Factors: IS ServicesEvaluation Factors: IS ServicesEvaluation Factors: IS ServicesEvaluation Factors: IS Services

24-SEP-2001






24-SEP-2001


Any new way of doing things generates some resistance by the people affected. Thus, implementation of new E-Business technologies can generate fear & resistance to change by employees & managers. To reduce user resistance to change, change must be managed.

Challenges for Managing Technological ChangeChallenges for Managing Technological ChangeChallenges for Managing Technological ChangeChallenges for Managing Technological Change

24-SEP-2001


ChangeManagement

Measurementand

Rewards

OrganizationalDesign

CoreCompetenciesDevelopment

Educate andTrain

UserInvolvement

Challenges for Managing Technological Change Challenges for Managing Technological Change (cont’d)(cont’d)Challenges for Managing Technological Change Challenges for Managing Technological Change (cont’d)(cont’d)

24-SEP-2001


Change management involves managing the people & the processes of organisational change. This can include:

Educating employees on the need for change

Recruiting & training employees in core competencies

Developing innovative ways to measure, motivate, & reward performance


24-SEP-2001


Analysing the impact of change before committing it

Encouraging direct user involvement in organisational change & system development efforts

Making change part of the organisational culture (Develop a change action plan, Develop change teams & change sponsors)

Working within the company culture not around it


24-SEP-2001


Information Systems Development & Management

:

Managing Information Systems

Next WeekNext WeekNext WeekNext Week

Date post:	30-Dec-2015
Category:	Documents
Upload:	leona-griffith
View:	223 times
Download:	2 times

Information Systems Overview (COIS 20024) Lecture: Week 10 Developing Information Systems...

Documents