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Transcript

  • 1. Chapter 6
  • 2. Chapter Objectives
    • Describe software trends, including the concept of software as a service
    • Explain software acquisition alternatives, including traditional and Web-based software development strategies
    • Describe software outsourcing options, including offshore outsourcing and the role of service providers
  • 3. Chapter Objectives
    • Explain advantages and disadvantages of in-house software development
    • Explain cost-benefit analysis and financial analysis tools
    • Explain the differences between a request for proposal (RFP) and a request for quotation (RFQ)
  • 4. Chapter Objectives
    • Describe the system requirements document
    • Explain the transition from systems analysis to systems design, and the importance of prototyping
    • Discuss guidelines for system design
    • Describe future software development trends
  • 5. Introduction
    • Chapter 6 describes the remaining activities in the systems analysis phase
    • The chapter also describes the transition to systems design, prototyping, and systems design guidelines
    • The chapter concludes with a discussion of future trends in software development
  • 6. Development Strategies Overview
    • Selecting the best development path is an important decision that requires companies to consider three key topics
      • The impact of the Internet
      • Software outsourcing options
      • In-house software development alternatives
  • 7. The Impact of the Internet
    • Traditional model
      • Software vendors develop and sell application packages.
      • Customers buy licenses.
      • Accounts for most software acquisitions.
    • Software as a Service (SaaS)
      • The Software and Information Industry Association (SIIA) believes that the concept of software as a service is redefining the way that companies develop and deploy their information systems.
      • Web-based services remove the responsibility for installation, maintenance, and upgrades.
  • 8. The Impact of the Internet
    • Traditional vs. Web-Based Systems Development
      • Internet-based systems use the Web as an integral part of the application, rather than just a communications channel.
      • Development environments
        • WebSphere
        • Microsoft’s .NET
      • Many firms rely on traditional systems
        • Legacy systems not easily replaced
        • Or, do not require a Web component
  • 9. The Impact of the Internet
    • Traditional vs. Web-Based Systems Development
      • Traditional development (in-house, software purchase, or outside consultants)
        • Design is influenced by compatibility issues with legacy systems
        • Designed to run on local and wide-area company networks
        • Web-based features are treated as enhancements rather than core elements of the design
        • Require more desktop computing power
        • Security issues are less complex
  • 10. The Impact of the Internet
    • Traditional vs. Web-Based 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
        • Usually requires additional layers, called middleware
        • Easily scalable and can run on multiple hardware platforms
        • Acquire as a service rather than a product
        • Requires less desktop computing power
  • 11. Outsourcing
    • The Growth of Outsourcing
      • Outsourcing is the transfer of information systems development, operation, or maintenance to an outside firm for a fee on a temporary or long-term basis
      • Traditionally, firms outsourced IT tasks as a way of controlling costs and dealing with rapid technological change
      • Outsourcing has become part of an overall IT strategy for many organizations
  • 12. Outsourcing
    • The Growth of Outsourcing
      • A firm that offers outsourcing solutions is called a service provider
      • Application service providers (ASP)
        • Delivers a software application, or access to an application, by charging a usage or subscription fee
      • Internet business services (IBS) (also called managed hosting)
        • Provide Web-based support for transactions such as order processing, billing and CRM
  • 13. Outsourcing
    • 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 to the application
      • A usage model or transaction model charges a variable fee based on the volume of transactions or operations performed by the application
  • 14. Outsourcing
    • 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
      • Outsourcing also can affect day-to-day company operations and can raise some concerns
        • Sensitive data – security, confidentiality, quality
      • Overseas concerns: control, culture, communication, and security
  • 15. Outsourcing
    • Outsourcing Issues and Concerns
      • A company must review carefully issues relating to insurance, potential liability, licensing and information ownership, warranties, and disaster recovery
      • Mergers and acquisitions also can affect outsourcing clients
      • Outsourcing can be especially attractive to a company whose volume fluctuates widely, such as a defense contractor
  • 16. Outsourcing
    • Offshore Outsourcing
      • Global outsourcing
      • Many firms are sending IT work overseas at an increasing rate
  • 17. In-House Software Development Options
  • 18. 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
  • 19. In-House Software Development Options
    • Make or Buy Decision
      • Software vendors
      • Value-added reseller (VAR)
      • Horizontal application
      • Vertical application
  • 20. 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
      • Satisfy unique security requirements
  • 21. 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
  • 22. 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
  • 23. In-House Software Development Options
    • Creating User Applications
      • User applications in Word, Excel, Access
      • User interface to front-end a spreadsheet or database
      • Help desk or information center (IC)
        • Have to support the users with training and questions
      • Screen generators & report generators
      • There a data security concerns – limit to PC or restrictive user profiles
      • Makes the IT staff more productive because they can concentrate on the large more complex IT projects
  • 24. Role of the Systems Analyst
    • When selecting hardware and software, systems analysts often work on the evaluation and selection team
    • 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
    • Depending on the decision the systems analyst’s role will change
  • 25. Analyzing Cost and Benefits
    • Financial Analysis Tools
      • Payback Analysis
      • Return on investment (ROI)
      • Net present value (NPV)
    • Read Part 3, Financial Analysis Tools in the Toolkit & the PowerPoint presentation on the Lecture’s Web page
  • 26. Analyzing Cost and Benefits
    • Cost-Benefit Analysis Checklist
      • List each development strategy being considered
      • Identify all costs and benefits for each alternative. Be sure to indicate when costs will be incurred and benefits realized
      • Consider future growth and the need for scalability
      • Include support costs for hardware and software
  • 27. Analyzing Cost and Benefits
    • Cost-Benefit Analysis Checklist
      • Analyze various software licensing options and their fees
      • Apply the financial analysis tools to each alternative
      • Study the results and prepare a report to management
  • 28. The Software Acquisition Process
    • 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
  • 29. The Software Acquisition Process
    • Step 1: Evaluate the Information System Requirements
      • Prepare a request for proposal or quotation
        • Request for proposal (RFP)
        • Use an evaluation model with weights
        • Request for quotation (RFQ)
  • 30. The Software Acquisition Process Unweighted Evaluation Model
  • 31. The Software Acquisition Process Weighted Evaluation Model
  • 32. The Software Acquisition Process
    • 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
      • For vertical applications check industry trade journals and Web sites
  • 33. The Software Acquisition Process
    • Step 3: Evaluate the Alternatives
      • Existing users – references and site visits
      • Application testing – demo the software
      • Benchmarking – magazines, Web, and consulting firms
      • Match each package against the RFP features and rank the choices
  • 34. The Software Acquisition Process
    • Step 4: Perform Cost-Benefit Analysis
      • Identify and calculate TCO for each alternative you are considering
      • Part 3, Financial Analysis Tools
        • Use spreadsheets with charts and what-if scenarios
      • When you purchase software, licensing fees
      • Consider the cost of technical support
      • If you purchase a software package, consider a supplemental maintenance agreement
  • 35. The Software Acquisition Process
    • Step 5: Prepare a Recommendation
      • You should prepare a recommendation that evaluates and describes 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
  • 36. The Software Acquisition Process
    • Step 6: Implement the Solution
      • Implementation tasks will depend on the solution selected
      • Important to plan the implementation strategy in advance
      • 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
  • 37. 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
      • Write in the user’s business language
  • 38. Completion of Systems Analysis Tasks
    • Presentation to Management
      • Suggest presenting to the users and IT staff before management
      • Send the requirements document to your audience before the presentation
      • Topics: overview of project, summarize alternatives, timelines, costs, advantages and disadvantages
      • 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
  • 39. Completion of Systems Analysis Tasks
    • Presentation to Management
      • Depending 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
  • 40. The Transition to System Design
    • Preparing for Systems Design Tasks
      • It is essential to have an accurate and understandable system requirements document
    • The Relationship between Logical and Physical Design
      • The logical design defines the functions and features of the system and the relationships among its components (what)
      • The physical design of an information system is a plan for the actual implementation of the system (how)
  • 41. Systems Design Guidelines
    • The systems analyst must understand the logical design of the system before beginning the physical design of any one component
      • Data design – chapter 8
      • User interface – chapter 7
      • Architecture – chapter 9
      • The design process overlaps and you may work on the above components at the same time
      • System design specification – end product/deliverable of the design phase
  • 42. Systems Design Guidelines
  • 43. 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 effective if it meets requirements and constraints
        • 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
  • 44. 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 – hard-coded
        • Provide flexibility
          • drop-down lists
          • Parameter prompts
          • Default values
  • 45. Systems Design Guidelines
    • System Design Objectives
      • Data Considerations
        • Data should be entered into the system where and when it occurs because delays cause data errors
        • Data should be verified when it is entered, to catch errors immediately
        • Automated methods of data entry should be used whenever possible
        • Control access for data entry
  • 46. Systems Design Guidelines
    • System Design Objectives
      • Data Considerations
        • 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
  • 47. Systems Design Guidelines
    • System Design Objectives
      • Architecture considerations
        • Use a modular design
        • Design independent modules that perform a single function
  • 48. Systems Design Guidelines
    • Design Trade-Offs
      • Most design trade-off decisions that you will face come down to the basic conflict of quality versus cost
        • Example cutting back on testing or user training
      • Avoid decisions that achieve short-term savings but might mean higher costs later
      • Conflicting requirements from different users
      • Final decision should be made by the users
  • 49. Prototyping
    • Prototyping Methods
      • System prototyping
        • Final system
      • Design prototyping
        • Throwaway prototyping
  • 50. 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
      • Consider potential problems
        • The rapid pace of development can create quality problems
        • In very complex systems, the prototype becomes unwieldy and difficult to manage
  • 51. Prototyping
    • Prototyping Tools
      • Systems analysts can use powerful tools to develop prototypes
        • CASE tools
        • Application generators
        • Report generators
        • Screen generators
        • Fourth-generation language (4GL)
        • Fourth-generation environment
  • 52. 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
  • 53. Future Trends in Software Development
    • Many software development tools and technologies are in transition
      • Web services becoming very popular
      • Open source software is growing
      • Development platforms like .NET continue to grow and Microsoft is the strongest leader
      • Service-oriented architecture (SOA)
        • Loose coupling
      • Software quality is more important than ever
        • Increased need for testing due to 9/11 to protect against physical attack and electronic intrusion
  • 54. Chapter Summary
    • This chapter describes system development strategies, the preparation and presentation of the system requirements document, and the transition to the systems design phase of the SDLC
    • An important trend that views software as a service, rather than a product, has created new software acquisition options
    • Systems analysts must consider Web-based development environments
  • 55. Chapter Summary
    • The systems analyst’s role in the software development process depends on the specific development strategy
    • The most important factor in choosing a development strategy is total cost of ownership (TCO)
    • The process of acquiring software involves a series of steps
    • Chapter 6 complete