Post on 23-Dec-2015
transcript
CHAPTER OUTLINE
13.1 Planning for and Justifying IT Applications13.2 Strategies for Acquiring IT Applications13.3 The Traditional Systems Development Life
Cycle13.4 Alternative Methods and Tools for
Systems Development13.5 Vendor and Software Selection
LEARNING OBJECTIVES
1. Define an IT strategic plan, identify three objectives it must meet, and describe the four common approaches to cost-benefit analysis.
2. Discuss the four business decisions that companies must make when they acquire new applications.
3. Identify the six processes involved in the systems development life cycle, and explain the primary tasks and importance of each process.
LEARNING OBJECTIVES (continued)
4. Describe four alternative development methods and four tools that augment development methods, and identify at least one advantage and one disadvantage of each method and tool.
5. Analyze the process of vendor and software selection.
13.1 Planning for and Justifying IT Applications
Organizations must analyze the need for the IT application.
Each IT application must be justified in terms of costs and benefits.
The application portfolio
Information Systems Planning (continued)
Organizational Strategic Plan IT Architecture
IT Strategic Plan
IS Operational Plan
Contains the following elements:MissionIT environmentObjectives of the IT functionConstraints of the IT functionApplication portfolioResource allocation and project management
Evaluating & Justifying IT Investment: Benefits, Costs & Issues
Assessing the costsFixed costs
Total cost of ownership (TCO)
Assessing the benefits (Values)Intangible benefits: Benefits from IT that may be very desirable but difficult to place an accurate monetary value on.
Comparing the two
Conducting the Cost-Benefit Analysis
Using Net Present Value (NPV)
Return on investment
Breakeven analysis
The business case approach
13.2 Strategies for Acquiring IT Applications
Four fundamental business decisions to make before choosing a strategy:
(1) How much computer code does the company want to write?
(2) How will the company pay for the application?
(3) Where will the application run?
(4) Where will the application originate?
Strategies for Acquiring IT Applications
Purchase a Prewritten Application
Customize a Prewritten Application
Lease the applications
Application Service Providers and Software-
as-a-Service Vendors
Use Open-Source Software
Outsourcing
Custom Development
Operation of an Application Service Provider (ASP)
ASP Data Center
CustomerA
Application
CustomerB
Application
CustomerC
Application
Database Database Database
Operation of a Software-as-a-Service (SaaS) Vendor
SaaS Vendor Data Center
CustomerA
CustomerB
CustomerC
CustomerA
CustomerB
CustomerC
Application
13.3 Traditional Systems Development Life Cycle
Software Development Life Cycle (SDLC) Systems InvestigationSystems AnalysisSystems DesignProgramming and TestingImplementationOperation and Maintenance
Prototyping
Six-Stage Systems Development Life Cycle (SDLC) with Supporting Tools
Systems Investigation
Deliverable: Go/No Go Decision
Systems Analysis
Deliverable: User Requirement
Systems Design
Deliverable: Technical Specification
Programming and Testing
ImplementThe
System
Operation and Maintenance
Business Need
Joint Application
Design (JAD)
Upper CASE Tools
Lower CASE Tools
The SDLC
Major advantagesControl
Accountability
Error detection
Major drawbacksRelatively inflexible
Time-consuming and expensive
Discourages changes once user requirements are gathered
SDLC – Systems Investigation
Begins with the business problem (or opportunity) followed by the feasibility analysis.
Feasibility study
Deliverable: Go/No-Go Decision
Feasibility Study
Technical feasibility
Economic feasibility
Organizational feasibility
Behavioral feasibility
SDLC – System Analysis
The examination of the business problem that the organization plans to solve with an information system.
Main purpose is to gather information about existing system to determine requirements for the new or improved system.
Deliverable is a set of system requirements, also called user requirements.
SDLC – Systems Design
Describes how the system will accomplish this task.
Deliverable is the technical design that specifies:
System outputs, inputs, user interfaces.
Hardware, software, databases, telecommunications, personnel & procedures.
Blueprint of how these components are integrated.
SDLC – System Design (continued)
Scope creep is caused by adding functions after the project has been initiated.
Kajano/Shutterstock
SDLC – Programming & Testing
Programming involves the translation of a system’s design specification into computer code.
Testing checks to see if the computer code will produce the expected and desired results under certain conditions.
Testing is designed to delete errors (bugs) in the computer code.
SDLC – Systems Implementation
Implementation involves three major conversion strategies:
Direct Conversion
Pilot Conversion
Phased Conversion
Parallel Conversion (not used much today)
SLDC – Operation & Maintenance
Audits are performed to assess the system’s capabilities and to determine if it is being used correctly.
Systems need several types of maintenance. Debugging
Updating
Maintenance
13.4 Alternative Methods and Tools for Systems Development
Joint application design (JAD)
Rapid application development (RAD)
Agile development
End-user development
Tools for Systems Development
Prototyping
Integrated computer-assisted software engineering (ICASE)
Component-based development
Object-oriented development
13.5 Vendor & Software Selection
Step 1: Identify potential vendors.
Step 2: Determine the evaluation criteria.Request for proposal (RFP)
Step 3: Evaluate vendors and packages.
Step 4: Choose the vendor and package
Step 5: Negotiate a contract.
Step 6: Establish a service level agreement.