Systems Analysis Design Eighth Edition Chapter 7 Development

Systems Analysis & Design Eighth Edition Chapter 7 Development Strategies

Introduction ● Chapter 7 describes the remaining activities in the systems analysis phase ● The chapter also describes the transition to systems design, prototyping, and systems design guidelines 2

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 3

The Impact of the Internet ● 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 Webbased development compares to traditional methods 4

The Impact of the Internet ● 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 – Cloud computing would be an ultimate form of Saa. S ● Web 2. 0 – Enable people to collaborate, interact, and share information more easily 5

The Impact of the Internet ● 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 6

The Impact of the Internet ● The Impact of the Internet on Systems Development – Developers will focus on Web-based application development, where the Web becomes an integral part of the application rather than just a communication channel 7

The Impact of the Internet ● The Impact of the Internet on Systems Development – Traditional development • Systems 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 8

The Impact of the Internet ● The Impact of the Internet on Systems Development – Web-based development • Internet-based development treats the Web as the platform, rather than just a communication channel • Easily scalable and hardware independent • Treat software as a service, not a commodity • Web-based software usually requires additional layers, called middleware, to communicate with existing software and legacy system 9

Salesforce. com: What is Cloud Computing? http: //www. youtube. com/watch? v=ae_DKN w. K_ms&feature=related 10

Outsourcing ● Can refer to relatively minor programming tasks, the rental of software from a service provider, the outsourcing of a basic business process (often called business process outsourcing, or BPO), or the handling of a company’s entire IT function 11

Outsourcing ● The Growth of Outsourcing – 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 ● 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 13

Outsourcing ● Outsourcing Issues and Concerns – Mission-critical IT systems should be outsourced only if the result is a cost-attractive, reliable, business solution that fits the company’s long-term business strategy – Outsourcing can be especially attractive to a company whose volume fluctuates widely, Ex. 處 理全國考試業務 14

Outsourcing ● Offshore Outsourcing – Offshore outsourcing – global outsourcing – Many firms are sending IT work overseas at an increasing rate – Gartner, a leading IT research and consulting firm, predicts that by 2005 one in 10 IT jobs at U. S. IT companies and one in 20 at non-IT companies will move offshore – Read “The World Is Flat” 15

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, e. g. Excel, Word 16

In-House Software Development Options ● Make or Buy Decision (Fig. 7 -10, p. 291) – The choice between developing versus purchasing software often is called a make or buy, or build or buy decision – Companies that develop software for sale are called software vendors – Value-added reseller (VAR): add custom features on a commercial package 17

In-House Software Development Options ● Reasons for 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 18

In-House Software Development Options ● Reasons for 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 19

In-House Software Development Options ● Customizing a Software Package 1. You can purchase a basic package that vendors will customize to suit your needs 2. You can negotiate directly with the software vendor to make enhancements to meet your needs by paying for the changes 3. You can purchase the package and make your own modifications, if this is permissible under the terms of the software license 20

Role of the Systems Analyst ● When selecting hardware and software, systems analysts often work as an 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 21

The Software Acquisition Process ● Step 1: Evaluate the Information System Requirements – Prepare a request for proposal or quotation • Request for proposal (RFP) 系統建議邀約, P. 301 • Evaluation model, P. 302 • Request for quotation (RFQ) 報價書邀約: 已知要買的東 西, p. 303 22

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 system that contains thousands of forums, called newsgroups 23

The Software Acquisition Process ● Step 3: Evaluate the Alternatives – Existing users – Application testing – Benchmarking – benchmark testing: ex. Testing the time needed to post 1, 000 sales transactions – Match each package against the RFP features and rank the choices 24

The Software Acquisition Process ● 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 supplemental maintenance agreement 25

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 26

The Software Acquisition Process ● 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 27

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 28

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, the objectives of this presentation, and what decisions need to made – Summarize the primary viable alternatives. For each alternative, describe the costs, advantages, and disadvantages 29

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 30

Completion of Systems Analysis Tasks ● Presentation to Management – Based on their decision, your next task will be one of the following 1. 2. 3. 4. 5. Implement an outsourcing alternative Develop an in-house system Purchase or customize a software package Perform additional systems analysis work Stop all further work 31

The Transition to Systems 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 32

The Transition to Systems 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 33

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 – User interface – Systems design specification 34

Systems Design Guidelines ● Systems Design Objectives – The goal of systems design is to build a system that is effective, reliable, and maintainable – Some considerations examples 35