1. Development Strategies
Chapter 5
Development Strategies

2. Introduction
Chapter 5 describes the remaining activities in the systems analysis phase
The chapter also describes the transition to systems design, prototyping, design guidelines 4

3. Development Strategies Overview
Selecting the best development path is an important decision that requires companies to consider three key issues
Web-based software trends
Software outsourcing options
In-house software development alternatives

4. Web-Based Software Trends
The Internet has triggered enormous changes in business methods and operations, and software acquisition is no exception
This section examines a trend that views software as a service, the changing market-place for software, and how Web-based development compares to traditional methods

5. Web-Based Software Trends
Software as a Service
The Software and Information Industry Association (SIIA) is an industry group that focuses on the digital economy
SIIA believes that the concept of software as a service is redefining the way that companies develop and deploy their information systems

6. Web-Based Software Trends
The Changing Software Marketplace
In the traditional model, software vendors develop and sell application packages to customers
In addition to traditional vendors, the marketplace now includes many forms of outsourcing, including application service providers and firms that offer Internet business services

7. Web-Based Software Trends
The Impact of the Internet on Systems Development
Developers will focus on Web-based application development, which builds the Web into the application, rather than the other way around
IBM’s WebSphere
Microsoft’s .NET

8. Web-Based Software Trends
The Impact of the Internet on Systems Development
Traditional development
System design is influenced by compatibility issues
Systems are designed to run on local and wide-area company networks
Web-based features are treated as enhancements rather than core elements of the design

9. Web-Based Software Trends
The Impact of the Internet on Systems Development
Web-based development
Systems are developed and delivered in an Internet-based framework such as .NET or WebSphere
Internet-based development treats the Web as the platform, rather than just a communication channel
Web-based software usually requires additional layers, called middleware

10. Software Outsourcing Options
Outsourcing is the transfer of information systems development, operation, or maintenance to an outside firm that provides these services, for a fee, on a temporary or long-term basis
Can refer to relatively minor programming tasks or the handling of a company’s entire IT function

11. Software Outsourcing Options
The Growth of Outsourcing
Traditionally, firms outsourced IT tasks as a way of controlling costs and dealing with rapid technological change
Today, outsourcing is a vital business issue that shapes a company’s overall IT strategy
the most important factor is the potential saving in operating costs

12. Software Outsourcing Options
The Growth of Outsourcing
A firm that offers outsourcing solutions is called a service provider
Application service providers (ASP)
Internet business services (IBS)
Also called managed hosting

13. Software Outsourcing Options
Outsourcing Fees
A fixed fee model uses a set fee based on a specified level of service and user support
A subscription model has a variable fee based on the number of users or workstations that have access
A usage model or transaction model charges a variable fee based on the volume of transactions or operations

14. Software Outsourcing Options
Outsourcing Issues and Concerns
Mission-critical IT systems should be out-sourced only if the result is a cost-attractive, reliable, business solution that fits the company’s long-term business strategy

15. Software Outsourcing Options
Outsourcing Issues and Concerns
A company must plan outsourcing carefully to avoid lost revenue, added expenses, and potential litigation
The solution can be only as good as the outsourcing firm that provides the service
A major disadvantage of outsourcing is that it raises employee concerns about job security

16. In-House Software Development Options
A company can choose to develop its own systems, or purchase, possibly customize, and implement a software package
The most important consideration is total cost of ownership (TCO)
Companies also develop user applications designed around commercial software packages

17. In-House Software Development Options
Make or Buy Decision
The choice between developing versus purchasing software often is called a make or buy, or build or buy decision
The company’s IT department makes, builds, and develops in-house software
A software package is obtained from a vendor or application service provider.

18. In-House Software Development Options
Make or Buy Decision
Companies that develop software for sale are called software vendors
Value-added reseller (VAR)
A firm that enhances a commercial package by adding custom features and configuring it for a particular industry
Vertical application
Horizontal application

19. In-House Software Development Options
Developing Software In-House
Satisfy unique business requirements
Minimize changes in business procedures and policies
Meet constraints of existing systems
Meet constraints of existing technology
Develop internal resources and capabilities

20. In-House Software Development Options
Purchasing a Software Package
Lower costs
Requires less time to implement
Proven reliability and performance benchmarks
Requires less technical development staff
Future upgrades provided by the vendor
Input from other companies

21. In-House Software Development Options
Customizing a Software Package
You can purchase a basic package that vendors will customize to suit your needs
You can negotiate directly with the software vendor to make enhancements to meet your needs by paying for the changes
You can purchase the package and make your own modifications, if this is permissible under the terms of the software license

22. In-House Software Development Options
Creating User Applications
A user application utilizes standard business software
Help desk or information center (IC)
Screen generators
Report generators
Read-only properties

23. Role of the Systems Analyst
When selecting hardware and software, systems analysts often work as an evaluation and selection team
A team approach ensures that critical factors are not overlooked and that a sound choice is made

24. Role of the Systems Analyst
The primary objective of the evaluation and selection team is to eliminate system alternatives that will not work, rank the system alternatives that will work, and present the viable alternatives to management for a final decision

25. A Software Acquisition Example
Step 1: Evaluate the Information System Requirements
Identify key features
Consider network and web-related issues
Estimate volume and future growth
Specify hardware, software, or personnel constraints
Prepare a request for proposal or quotation
Request for proposal (RFP)建議書邀約
Evaluation model
Request for quotation (RFQ)報價書邀約

26. A Software Acquisition Example
Step 2: Identify Potential Vendors or Outsourcing Options
The Internet is a primary marketplace
Another approach is to work with a consulting firm
Another resource is the Internet bulletin board systems that contains thousands of forums, called newsgroups

27. A Software Acquisition Example
Step 3: Evaluate the Alternatives
Existing users
Application testing
Benchmarks 標竿測試
Match each package against the RFP features and rank the choices

28. A Software Acquisition Example
Step 4: Perform Cost-Benefit Analysis
Identify and calculate TCO for each option you are considering
When you purchase software, what you are buying is a software license
If you purchase a software package, consider a maintenance agreement

29. A Software Acquisition Example
Step 5: Prepare a Recommendation
You should prepare a recommendation that contains your recommendation and lists the alternatives, together with the costs, benefits, advantages, and disadvantages of each option
At this point, you may be required to submit a formal system requirements document and deliver a presentation

30. A Software Acquisition Example
Step 6: Implement the Solution
Implementation tasks will depend on the solution selected
Before the new software becomes operational, you must complete all implementation steps, including loading, configuring, and testing the software; training users; and converting data files to the new system’s format

31. Completion of Systems Analysis Tasks
System Requirements Document
The system requirements document, or software requirements specification, contains the requirements for the new system, describes the alternatives that were considered, and makes a specific recommendation to management
Like a contract
Format and organize it so it is easy to read and use

32. Completion of Systems Analysis Tasks
Presentation to Management
Begin your presentation with a brief overview of the purpose and primary objectives of the system project
Summarize the primary viable alternatives. For each alternative, describe the costs, advantages, and disadvantages

33. Completion of Systems Analysis Tasks
Presentation to Management
Explain why the evaluation and selection team chose the recommended alternative
Allow time for discussion and for questions and answers
Obtain a final decision from management or agree on a timetable for the next step in the process

34. Completion of Systems Analysis Tasks
Presentation to Management
Based on their decision, your next task will be one of the following
Implement an outsourcing alternative
Develop an in-house system
Purchase or customize a software package
Perform additional systems analysis work
Stop all further work

35. The Transition to System Design
If management decides to develop the system in-house, then the transition to the systems design phase begins
Preparing for Systems Design Tasks
It is essential to have an accurate and understandable system requirements document

36. The Transition to System Design
The Relationship between Logical and Physical Design
The logical design defines the functions and features of the system and the relationships among its components
The physical design of an information system is a plan for the actual implementation of the system

37. Systems Design Guidelines
System Design Objectives
The goal of systems design is to build a system that is effective, reliable, and maintainable
A system is reliable if it adequately handles errors
A system is maintainable if it is well designed, flexible, and developed with future modifications in mind

38. Systems Design Guidelines
System Design Objectives
User considerations
Carefully consider any point where users receive output from, or provide input to, the system
Anticipate future needs of the users, the system, and the organization
Provide flexibility
Parameter, default
Data Considerations
Data should be entered into the system where and when it occurs because delays cause errors
Data should be verified when entered to catch errors immediately

39. Systems Design Guidelines
System Design Objectives
Data Considerations
Automated methods of data entry should be used whenever possible
Access for data entry should be controlled and all entries or changes to critical data values should be reported – audit trails
Every instance of entry and change to data should be logged
Data should be entered into a system only once
Data duplication should be avoided

40. Systems Design Guidelines
System Design Objectives
Architecture considerations
Use a modular design
Design modules that perform a single function are easier to understand, implement, and maintain

41. Prototyping
Prototyping produces an early, rapidly constructed working version of the proposed information system, called a prototype
Prototyping allows users to examine a model that accurately represents system outputs, inputs, interfaces, and processes

42. Prototyping
Prototyping Methods
System prototyping
Design prototyping

43. Prototyping Prototyping Methods Prototyping offers many benefits
Users and systems developers can avoid misunderstandings
Managers can evaluate a working model more effectively than a paper specification
Also consider potential problems
The rapid pace of development can create quality problems
In very complex systems, the prototype becomes unwieldy and difficult to manage

44. Prototyping Prototyping Tools
Systems analysts can use powerful tools to develop prototypes
CASE tools
Application generators
Report generators
Screen generators
Fourth-generation languages (4GLs)

45. Prototyping Limitations of Prototypes
A prototype is a functioning system, but it is less efficient than a fully developed system
Systems developers can upgrade the prototype into the final information system by adding the necessary capability
Otherwise, the prototype is discarded