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System Analysis and Design Rabie A. Ramadan, PhD http://rabieramadan.org 2 30/3/2011
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SYSTEM DEVELOPMENT METHODOLOGIES 1 - 2
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Rapid Application Development (RAD) 1 - 3 Incorporate special techniques and tools: CASE tools JAD sessions Fourth generation/visualization programming languages Code generators
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CASE tools 1 - 4 Computer-aided software engineering (CASE) Scientific application of a set of tools and methods to a software system which is meant to result in high- quality, defect-free, and maintainable software products. Modeling business / real-world processes and data flow. Development of data models in the form of entity-relationship diagrams
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JAD sessions 1 - 5 Joint Application Development (JAD) Developed by Drake and Josh of IBM IBM Toronto in a workshop setting. JAD was designed to bring system developers and users of varying backgrounds and opinions together in a productive as well as creative environment.
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Three RAD Categories 1 - 6 Phased development A series of versions developed sequentially Prototyping System prototyping Throw-away prototyping Design prototyping
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Phased Development Methodology 1 - 7 Insert Figure 1-4 here
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Pros and Cons of Phased Development Methodology 1 - 8 ProsCons Users Get a System To Use Quickly Users Can Identify Additional Needs For Later Versions Users Work with a System that is Intentionally Incomplete
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How Prototyping Works 1 - 9
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Pros and Cons of Prototyping Methodology 1 - 10 ProsCons Users Interact with Prototype Very Quickly Users Can Identify Needed Changes And Refine Real Requirements Tendency to do Superficial Analysis Initial Design Decisions May Be Poor
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Throwaway Prototyping 1 - 11
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Pros and Cons of Throwaway Prototyping Methodology 1 - 12 ProsCons Risks are Minimized Important Issues are Understood Before the Real System is Built May Take Longer Than Prototyping
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Agile Development: Extreme Programming 1 - 13
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Pros and Cons of Agile Methodologies 1 - 14 ProsCons Fast Delivery of Results Works Well in Projects With Undefined or Changing Requirements Requires Discipline Works Best in Small Projects Requires Much User Input
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Criteria for Selecting the Appropriate Methodology 1 - 15 Clear user requirements Familiarity with technology Complexity of system Reliability of system Time schedule Schedule visibility
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TEAM ROLES AND SKILLS 1 - 16
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Information Systems Roles 1 - 17 Business analyst Systems analyst Infrastructure analyst Change management analyst Project manager
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Summary 1 - 19 The Systems Development Lifecycle consists of four stages: Planning, Analysis, Design, and Implementation There are six major development methodologies: the waterfall method, the parallel development method, the phased development method, system prototyping, design prototyping, and agile development. There are five major team roles: business analyst, systems analyst, infrastructure analyst, change management analyst and project manager.
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20 Project Initiation
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Key Ideas 2 - 21 An opportunity to create business value from using information technology initiates a project. Feasibility analysis helps determine whether or not to proceed with the IS project. Projects are selected based on business needs and project risks.
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Key Ideas 2 - 22 The project sponsor is a key person who identifies business value to be gained from using information technology. The approval committee reviews system requests from groups throughout the organization and selects projects for the benefit of the business.
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Why a new system? 2 - 23 Problem Orientation Define the problem Establish system objectives Identify the USERS Establish functional scope
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IDENTIFYING PROJECTS WITH BUSINESS VALUE 2 - 24
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Why Implement a new system? 2 - 25 Capability Communication Control Cost Competitive advantage
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Why Implement a new system? 2 - 26 Capability: Efficiency Capability: Efficiency improve processing speed ability to handle increased volume PC vs. manual methods, more PC's, LAN faster retrieval of information Bigger, faster data storage, SQL-based DBMS Canned- software (Order entry, Manufacturing, etc.)
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Why Implement a new system? 2 - 27 Control: Efficiency/Effectiveness Improved accuracy and consistency automating the process to reduce human error Computer prompting, error detection, field value checks Provide better security Need to know screens Password protection
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Why Implement a new system? 2 - 28 Communication: Effectiveness Enhance communication Credit card systems, E-Mail Integration of business areas: Coordination LAN communication, Manufacturing systems
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Why Implement a new system? 2 - 29 Cost: Effectiveness Monitor Costs Tracking cost through a system (manufacturing LED-CS) Reducing costs automatic calculation-retrieval systems
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Why Implement a new system? 2 - 30 Competitive Advantage: Effectiveness: a strategic weapon Lock in customers by offering a better price by providing a unique service by presenting distinctive products Lock out competitors Improve arrangement with suppliers
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Preliminary Project Acceptance System request is reviewed by approval committee Based on information provided, project merits/values are assessed. Worthy projects are accepted and undergo additional investigation – the feasibility analysis.
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How Do Projects Begin? Business needs should drive projects. Project sponsor recognizes business need for new system and desires to see it implemented. Business needs determine the system’s functionality (what it will do). The project’s business value should be clear.
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System Request A document describing business reasons for project and system’s expected value. Lists project’s key elements Project sponsor Business need Business requirements Business value Special issues or constraints
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System Request Examples Project sponsor – Carrefour of Marketing Business need – Reach new customers and improve service to existing customers Business requirements – Provide web-based shopping capability Business value - $750,000 in new customer sales; $1.8M in existing customer sales Special issues or constraints – System must be operational by holiday shopping season
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Your Turn 2 - 35 If you were building a web-based system for course registration, What is the business need? Reach new and make easy on them to register What would be the business requirements? Computer System and Internet What would be the business value (tangible and intangible)? Tangible: new students, intangible: raise the rank of the univ. What special issues or constraints would you foresee? Expanding the IT department, maintenance, new budget
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FEASIBILITY ANALYSIS 2 - 36
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Feasibility Analysis 2 - 37 Detailed business case for the project Technical feasibility Economic feasibility Organizational feasibility Compiled into a feasibility study Feasibility is reassessed throughout the project
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Technical Feasibility: Can We Build It? Users’ and analysts’ familiarity with the business application area Familiarity with technology Have we used it before? How new is it? Project size Number of people, time, and features Compatibility with existing systems
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Can we build it? 2 - 39 Feasibility Technical Do we have the capability to develop the system? Does the necessary tech exist? Can it be acquired? Does the proposed equipment have the right capacity for the data? Does the propose have the right: response time, interface, Can the system be expanded? Are the accuracy, reliability, ease of use, ease of access, security ok?
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Economic Feasibility Should We Build It? Identify costs and benefits Assign values to costs and benefits Determine cash flow Assess financial viability Net present value Return on investment Assess Financial Viability
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Should we build it? 2 - 41 Economic Is there an economic payoff? include cost to conduct full systems integration cost of hardware/software/ other benefits in terms of reduced costs opportunity costs
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Assign Cost and Benefit Values Difficult, but essential to estimate Work with people who are most familiar with the area to develop estimates Intangibles should also be quantified If intangibles cannot be quantified, list and include as part of supporting material
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Identify Costs and Benefits 2 - 43 CostsBenefits Tangible Intangible ************ ************
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Determine Cash Flow
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Assess Financial Viability – Net Present Value (NPV) NPV = PV(future cash inflows) – PV(future cash outflows) PV = Cash flow amount (1 + interest rate) n, where interest rate = required return n = number of years in future
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Determine NPV If NPV >= 0, Project is OK If NPV < 0, Project is unacceptable
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Assess Financial Viability – Return on Investment ROI = NPV PV(cash outflows)
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Assess Financial Viability – Break Even Point How long before the project’s returns match the amount invested The longer it takes to break even, the higher the project’s risk.
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Organizational Feasibility If we build it, will they come? Strategic alignment How well do the project goals align with business objectives? Stakeholder analysis Project champion(s) Organizational management System users
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Why a new system? 2 - 50 Organizational Is there support/resistance; from or by who Are current business methods acceptable? If not a change may be welcomed Have the user's been involved? If not get them involved Will the system cause harm?
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What is Expected? 2 - 51 The EXPECTED RESULTS SATISFIES the organizations requirements operates RELIABLY creates an "appropriate" working environment is MAINTAINABLE is MODIFIABLE is ADAPTABLE to a changing environment has controls to ensure: security privacy audibility -
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What is expected 2 - 52 A. Objectives of System Analysis To establish in detail what the systems is to do objectives costs benefits implementation process organizational changes required INNOVATION defines who the USERS are Their input and output THE SYSTEM FLOW
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Why a new system? 2 - 53 Alternative Specification Propose options Make versus buy decisions Cost-Benefit analysis Assess project risk Recommend Unwritten- find allies
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PROJECT SELECTION 2 - 54
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Project Selection Issues Approval committee works from the system request and the feasibility study Project portfolio – how does the project fit within the entire portfolio of projects? Trade-offs must be made to select projects that will form a balanced project portfolio Viable projects may be rejected or deferred because of project portfolio issues.
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Summary 2 - 56 Project initiation involves creating and assessing goals and expectations for a new system Identifying the business value of the new project is a key to success Feasibility study is concerned with insuring that technical, economic, and organizational benefits outweigh costs and risks Project selection involves viewing the project within the context of the entire project portfolio, and selecting those projects that contribute to balance in the portfolio
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Your Project During the Semester 2 - 57 Step 1: Since you are here at Future University, Define the needed projects for the University and asses their feasibility. Write a complete proposal by the next week in a doc file I will asses your proposals and approve one
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