Systems Development Lifecycle (SDLC)

Jason C. H. Chen (陳周宏 ), Ph.D.Visiting Professor

National Taipei University of TechnologyProfessor of MIS

Graduate School of Business AdministrationGonzaga University

Spokane, WA 99258 USAJason8989.chen@gmail.com

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What Are Systems Development Activities?

1. Systems definition/investigation Management’s statement of objective and goals for

new system2. Requirements analysis

Identify features and functions3. Component design (hardware, software,

network) Based on approved user requirements

4. Implementation Purchase, build, test, and convert to new system

5. System maintenance (fix or enhance) Repair, add new features, maintain

Analysis

What Are Systems Development Activities?

BPM Provides Requirements for Systems Development 3

[1]

[2]

[4]

[3a]

[3b]

[5]

(Feasibility Study)What is it and Why it is important?

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Assess Feasibility

Dimensions of feasibility• _______________ feasibility

Approximated, “back-of-the-envelope” analysis Purpose: eliminate infeasible ideas early Consider cost of previous projects, operational and labor

costs• __________ feasibility

Ball park estimate• __________ feasibility

Is it technically likely to meet needs?• _____________ feasibility

Fit with customs, culture, charter, legal requirements of organization

___________________ feasibility Is the proposed system legally?

Cost/Economic

Schedule

Technical

Organizational

Legal and Contractual

Systems Definition/Investigation (Feasibility Study)

OperationalFeasibility

ScheduleFeasibility

EconomicFeasibility

TechnicalFeasibility

Can we afford it? Will it be accepted?

Does the ITcapability exist?

Will it be completed bythe deadline?

Legal and Contractual Feasibility

Is the proposed system legally?

Organizational Feasibility(Is it a good fit –

objective of the organization5

What are new from the last slide?

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Form a Project Team• Typical three personnel on a development team are:

Manager (or mangers for larger projects) Specialist:

System analysts Programmers Software testers or, other functional specialist such as accounting,

finance, and marketingUsers:

Users must be involved in most of SDLC phases • Depending on nature of project, team may also include

hardware and communications specialists, database designers and administrators, and other IT specialists.

Systems Development

• What happen (and Why) to a project in the Department of Interior of Taiwan?

Phase Four: Implementation

8Fig 10-18: SDLC: Implementation Phase

Focuses on implementing the system and includes the tasks of building each of the

five system components

testing the systemand

converting users to the new system.

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System Conversion Approaches

1. Pilot Implement entire system in limited portion of

business MRV uses system for selected customers. Advantage: limits exposure to business if system fails

2. Phased System is installed in phases or modules. Each piece is installed and tested.

3. Parallel Complete new and old systems run simultaneously Very safe, but expensive

4. Plunge (or direct) High risk if new system fails, no old system to fall

back on Only used if new system is not vital to company

operation

Installation Conversion Methods: 4 Ps

Old System New System

Old System

New System

Old System New System

Old System New System

Parallel

Pilot

Phased

Plunge/Direct

Cut-over time

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Causes of Information Systems Failures

•35+ years of research on causes of information systems failures

1. Lack of user __________2. Unclear, incomplete, and inconsistent

___________3. Changing requirements and

specifications•Many businesses __________ research findings

involvement.

requirements.

ignore

Systems Development Lifecycle (SDLC)