Systems Analysis and Design PDF
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Roberta Roth, Alan Dennis, and Barbara Haley Wixom
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This document is a chapter from a textbook about systems analysis and design. It provides an overview of the systems development life cycle (SDLC) and the role of a systems analyst in information systems development. It details the various phases involved in the SDLC, including planning, analysis, design, and implementation, also discussing important concepts such as system request and feasibility analysis.
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Systems Analysis and Design 5th Edition Chapter1: The Systems Analyst and Information Systems Development Roberta Roth, Alan Dennis, and Barbara Haley Wixom Chapter 1 Outline The systems analyst. The Systems Development Life Cycle (SDLC). Information system project iden...
Systems Analysis and Design 5th Edition Chapter1: The Systems Analyst and Information Systems Development Roberta Roth, Alan Dennis, and Barbara Haley Wixom Chapter 1 Outline The systems analyst. The Systems Development Life Cycle (SDLC). Information system project identification and initiation. Be able to create a system request. Feasibility analysis. 2 Introduction The systems development life cycle (SDLC) is the process of determining how an information system (IS) can support business needs, designing the system, building it, and delivering it to users. The key person in the SDLC is the systems analyst, who analyzes the business situation, identifies the opportunities for improvements, and designs an IS to implement the improvements. 3 Systems Analyst Skills The systems analyst plays a key role in IS development projects. The following are the skills that the systems analyst should have: Technical – Must understand the technical environment, technical foundation, and technical solution. Business – Must understand how IT can be applied to business situations. Analytical – Must be problem solvers. 4 Systems Analyst Skills(cont’d) Interpersonal skills – Need to communicate effectively. Management – Need to manage people and to manage pressure and risks. Ethical - Must deal fairly, honestly, and ethically with other project members, managers, and systems users. 5 Systems Analyst Roles Business analyst - Focuses on the business issues surrounding the system. System analyst - Focuses on the IS issues surrounding the system Infrastructure analyst - Focuses on technical issues Change management analyst - Focuses on the people and management issues surrounding the system installation. Project manager - Ensures that the project is completed on time and within budget, and that the system delivers the expected value to the organization. Requirements Analyst- Focus on eliciting the requirements from the stakeholders associated with the new system. 6 The Systems Development Life Cycle (SDLC) The SDLC is composed of four fundamental phases: 1) Planning 2) Analysis 3) Design 4) Implementation 7 SDLC (cont’d) Each of the sequential SDLC phases is composed of consecutive steps and activities, which rely on appropriate tools and techniques(models & templates) that produce deliverables (specific documents that explain various elements of the system). 8 Planning Phase This phase is the fundamental process of understanding why an information system should be built , and determining how the project team will go about building it. By “Problems” that need solving , we mean: ◼ Problems either real or anticipated, that require corrective action. ◼ Opportunities to improve a situation despite the absence of complaints. ◼ Directives to change a situation regardless of whether anyone has complained about the current situation by management, government, or some external influence. 9 The planning phase has two steps: 1. During project initiation, the system’s business value to the organization is identified (How will it lower costs or increase revenues?). 2. During project management, the project manager creates a work plan, staffs the project, and puts techniques in place to help the project team control and direct the project through the entire SDLC. 10 Analysis Phase The analysis phase answers the questions of who will use the system, what the system will do, and where and when it will be used. During this phase the project team investigates any current system(s), identifies improvement opportunities, and develops a concept for the new system. 11 The analysis phase has three steps: 1. Analysis strategy: This is developed to guide the projects team’s efforts. This includes a study of the current system and its problems, and envisioning ways to design a new system. 2. Requirements gathering: The analysis of this information leads to the development of a concept for a new system. This concept is used to build a set of analysis models. 3. System proposal: The proposal is presented to the project sponsor and other key individuals who decide whether the project should continue to move forward. 12 Design Phase The design phase decides how the system will operate, in terms of technical components : ◼ the hardware, software, and network infrastructure; ◼ the user interface, forms, and reports that will be used; and ◼ the specific programs, databases, and files that will be needed. 13 The design phase has four steps: 1. Design Strategy: This clarifies whether the system will be developed by the company or outside the company(Outsourcing firms). 2. Architecture Design: This describes the hardware, software, and network infrastructure that will be used. 3. Database and File Specifications: These documents define what and where the data will be stored. 4. Program Design: Defines what programs need to be written and what they will do. 14 Implementation Phase During the implementation phase, the system is either developed or purchased (in the case of packaged software) , tested and installed. Users training and educations. This phase is usually the longest and most expensive part of the process. 15 The implementation phase has three steps: 1. System Construction: The system is built and tested to make sure it performs as designed. 2. Installation: The old system is turned off and the new one is turned on. 3. Support Plan: Includes a post implementation review as well as a systematic way for identifying changes needed for the system. 16 Planning Phase in Details slides(from 18 to 37) Primary outputs: ▪ System Request with feasibility study ▪ project plan(Chapter2) 17 Project Identification and Initiation A project is identified when someone in the organization identifies a business need to build a system. A need may surface when an organization identifies unique and competitive ways of using IT, to leverage the capabilities of emerging technologies such as cloud computing, RFID….. etc. 18 Project sponsor The project sponsor is a person (or group) who has an interest in the system’s success The project sponsor will work throughout the SDLC to make sure that the project is moving in the right direction from the perspective of the business. The project sponsor serves as the primary point of contact for the project team. The project sponsor has the insights needed to determine the business value that will be gained from the system. 19 System Request The document that describes the business reasons for building a system and the value(benefits) that system is expected to provide. It has five elements: 1. The project sponsor usually completes this form as part of a formal system selection process within the organization. 2. Business need presents reasons prompting the project. 20 System Request (cont’d) 3. The business requirements of the project refer to the business capabilities that the system will need to have. 4. The business value describes the benefits that the organization should expect from the system. 5. Special issues are included on the document as a catchall category for other information that should be considered in assessing the project. 21 System Request Example See the “System Request Example” on slide number 39 22 System Request (cont’d) The completed system request is submitted to the approval committee(steering committee) for consideration. The committee reviews the system request and makes an initial determination of whether to investigate the proposed project or not. If so, the next step is to conduct a feasibility analysis. 23 Feasibility Analysis Feasibility analysis guides the organization in determining whether to proceed with a project. Feasibility analysis also identifies the important risks associated with the project that must be managed if the project is approved. 24 Feasibility Analysis(cont’d) As with the system request, each organization has its own process and format for the feasibility analysis, but most include techniques to assess three main areas: ◼ Technical feasibility ◼ Economic feasibility ◼ Organizational(Operational) feasibility The results of evaluating these three feasibility factors are combined into a feasibility study deliverable that is submitted to the approval committee at the end of project initiation. 25 Technical Feasibility Technical feasibility is the extent to which the system can be successfully designed, developed, and installed by the IT group. It is, in essence, a technical risk analysis that strives to answer the question: “Can we build it?” 26 Technical Feasibility(cont’d) Risks can endanger the successful completion of a project. The following factors should be considered: ◼ Familiarity with the application: Users’ and analysts’ should be familiar with the application. ◼ Familiarity with the technology ◼ Project size ◼ Compatibility of the new system with the technology that already exists 27 Economic Feasibility Economic feasibility analysis is also called a cost-benefit analysis, that identifies the costs and benefits associated with the system. This attempts to answer the question: “Should we build the system?” 28 Economic Feasibility(cont’d) Steps to conduct an economic feasibility analysis: 1. Identify Costs and Benefits 2. Assign Values to Costs and Benefits 3. Determine Cash Flow 4. Assess Project’s Economic Value - Return on Investment ROI - Break-Even Point BEP - Net present value NPV 29 1.Identify Costs and Benefits The costs and benefits be broken down in to four categories: ◼ Development costs ◼ Operational costs ◼ Tangible benefits ◼ Intangibles benefits Tangible value can be quantified and measured easily (reduction in operating costs). An intangible value results from an intuitive belief that the system provides important, but hard-to-measure benefits to the organization. 30 2.Assign Values to Costs and Benefits Once the types of costs and benefits have been identified, the systems analysts needs to assign specific dollar values to them. System Analysis and Design 31 3.Determine Cash Flow A formal cost-benefit analysis usually contains costs and benefits over a selected number or years(usually, three to five years) to show cash flow over time. Cash Flow Analysis and Measures: ▪ IT projects involve an initial investment that produces a steam of benefits over time, along with some on-going support costs. ▪ Cash flows, both inflows and outflows, are estimated over some future period. 32 Simple cash flow projection Net cash flow=cash inflow(year1)- cash outflow (year 1) net cash flow(year0)= 0 - 100,000 = -100,000 net cash flow(year1)= 45,000 - 10,000 = 35,000 net cash flow(year2)= 50,00 - 12,000 = 38,000 net cash flow(year3)= 57,000 - 16,000 = 41,000 Cumulative net cash flow= net cash flow(year1)+ net cash flow(year 2)+ net cash flow(year 3)………etc Cumulative net cash flow(year1 )= -100,000 + 35,000 = -65,000 Cumulative net cash flow(year2)= -65,000 + 38,000 = -27,000 Cumulative net cash flow(year3)= -27,000 + 41,000 = 14,000 33 4. Assess Project’s Economic Value Common methods for evaluating a project’s worth: 4.1 Return on Investment (ROI) 34 (Cont’d) 4.2 Break-Even Point (BEP) 35 Organizational Feasibility Organizational feasibility of the system is how well the system ultimately will be accepted by its users and incorporated into the ongoing operations of the organization. There are many organizational factors that can have an impact on the project, and seasoned developers know that organizational feasibility can be the most difficult feasibility dimension to assess. In essence, an organizational feasibility analysis is to answer the question “If we build it, will they come?” 36 Organizational Feasibility(cont’d) Tow main ways to assess the Organizational Feasibility: 1. to assess the organizational feasibility is to understand how well the goals of the project align with the business objectives and organizational strategies. 2. to assess the organizational feasibility is to conduct stakeholder analysis. A stakeholder is a person, group, or organization that can affect a new system - Project champion - Customer, Suppliers - System users - Competitors, Government - Organizational management - Other stakeholders 37 SUMMARY The Systems Analyst is the key person in the development of information systems. The Systems Development Lifecycle consists of four stages: Planning, Analysis, Design, and Implementation. Project Identification and Initiation recognize a business need that can be satisfied through the use of information technology. System Request describes the business value for an information system. A Feasibility Analysis is used to provide more detail about the risks associated with the proposed system. 38 FIGURE 1-5 System Request for Tune Source 39 System Analysis and Design 40