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O'Brien MIS, 6th ed. Topic 4 Developing and Implementing Information Systems * Learning Objectives Describe the system approach to problem solving Describe and Explain the steps of the systems development life cycle Explain the need for successful project management Compare different development approaches organizations can apply * The System Approach * * Systems development is needed when: Potential competition and developments in technology lead to the development of new systems to carry out an existing function Existing systems are modified to carry out additional functions Comply with regulations A system has ran through its full life cycle; 3 Phases: Development (e.g., SDLC), Effective operational use, and Decline in usefulness (McKeown 2000,p.221) Development Effective Operational Use Decline Percent of Effectiveness * The Systems Approach: “seeing the forest AND the trees” Seeing “interrelationships” among “systems” rather than linear cause-and-effect chains when events occur Seeing “processes” of change among “systems” rather than discrete “snapshots” of change, whenever change occurs. An example of system thinking: the sales processes * * Design the Solution Define the Problem Develop Alternative Solutions Select the Solution Implement the Solution Monitor and Evaluate Results Systems Approach to Problem Solving * About the System Approach Steps can overlap each other Activities required for problem solving can be used in more than one step of the process The completion of activities in one step may extend into the performance of another Sometimes you may have to cycle back to a previously completed step * Systems Development Life Cycle (SDLC) * * Systems Development Life Cycle (SDLC) When the system approach to problem solving is applied to the development of information systems solutions to business problems, it is called the system development life cycle (SDLC) All software development methodologies use (or build on or extend from) SDLC even though the way that they use it differs It is a common methodology the overall structure of cycle, of iteration, remains throughout-think of the cycle as an organizing and guiding principle Exists different life cycle models, with anywhere from three to almost twenty identifiable phases * Different SDLC Methods Traditional system approach (focus of this subject)-relevant for all projects (esp. large projects in large organizations). In an continuing effort to improve the systems analysis and design process, several other approaches have been developed Rapid Application Development (RAD): faster, use of prototype, heavy user involvement, and an iterative construction approach Extreme Programming (XP): breaks a project into tiny phases, and developers cannot continue on to the next phase until the first phase is complete. And within each phase, iteration will be done until satisfaction is achieved Agile method: A form of XP with less focus on team coding and more on limiting the scope-setting a minimum number of requirements and turns them into a deliverable product. On a related note, DevOPs is an extension of Agile method, including both development and operations. These methods are more suitable for smaller and more end-user focuses projects or some parts of the overall master project by smaller project teams. * 5-Step SDLC Model Suggested by O’Brien & Marakas (2011) * 7-Step SDLC Model Suggested by Haag et al. (2008) * * SDLC Discussion The following discussion of SDLC is based on Haag et al. (2008) 7-phase stage with complement information (i.e., discussion on system approach and on feasibility study) drawn from O’Brien and Marakas (2011). Please note that O’Brien (2011) classifies SDLC into five phases of Investigation, Analysis, Design, Implementation, and Maintenance. We use Haag et al. (2008)’s model to explain SDLC for the reasons of convenience and clearer explanation of steps/activities involved in the SDLC, it is recommended that you use Haag et al. (2008) model for your Assignment 2 and follow the slides discussed in this topic. Planning Phase * * Planning Phase Planning phase – involves establishing a high-level plan of the intended project and determining project goals Primary planning activities include Identify and select the system for development Assess project feasibility Develop the project plan * Planning: Identify and Select the System for Development * Organizations can use different forms of evaluation criteria to determine which systems to develop. * * Multicriteria Analysis for Project Selection (Hoffer et al. 2005) Each requirement or constraint: Rating = weight X Score Each alternative: sum scores across requirements/constraints Alternative with highest score wins Rating information could be attained via publications, experience, and consensus. * Some Factors for Project Selection Suggested by Hoffer et al. (2005) * Evaluation Practices in the early stage Any careful evaluation of all possible solutions could be very time-consuming and expensive A good first step is to eliminate solutions that do not meet the key selection criteria established by the organization (i.e., meeting mandatory requirements, exceeding the budget, and so on) The objective of such early stage evaluation is to reduce the number of candidates before a more thorough review is conducted. * Each stakeholder group brings their own perspective and motivation to the IS decision * Techniques for Choosing Strategic Projects by Haag et al. (2006) * * Planning 2: Assess Project Feasibility Feasibility study – determines if the proposed solution is feasible and achievable The approval of a large system request may not actually occur until after the feasibility study. Typically several alternative solutions will be looked at. Organizations could use different types of feasibility studies Feasibility study may be unnecessary: Government mandate * Some Commonly Used Feasibility Studies * * Cost/Benefit Analysis: Tangible and Intangible Costs Tangible costs: costs that can be quantified (e.g., cost of hardware and software, employee salaries, and other quantifiable costs needed to develop and implement a solution) Intangible costs: costs that can not be quantified (loss of customer goodwill or employee morale caused by errors and disruptions arising from the installation of a new system) * * Cost/Benefit Analysis: Tangible and Intangible Benefits * * Example: Some Costs and benefits of a new supply chain management system (Laudon & Laudon 2005) * Example: Some Financial models (Laudon & Laudon 2005) * Planning 3: Develop the Project Plan Project plan is a formal, approved document for project execution and addresses the time, scope, resources, and other issues of the proposed project. Developing the project plan is a difficult and important activity The project plan is the guiding force behind on-time delivery of a complete and successful system Continuous updating of the project plan must be performed during every subsequent phase during the SDLC * Analysis Phase * * Phase 2: Analysis Analysis phase – involves analyzing end-user business requirements and refining project goals into defined functions and operations of the intended system Primary analysis activities include Gather business requirements Create process diagrams Perform a buy vs. build analysis or Evaluate other alternatives (discussed later after SDLC steps) * * Analysis 1: Gather Business Requirements Business requirements – the detailed set of business requests that the system must meet in order to be successful Different ways to gather business requirements Joint application development (JAD) session – where employees meet to define or review the business requirements for the system Interviews Questionnaires Observations Review business documents * * Systems Analysis-Organizational Analysis Organizational analysis: to understand the organizational environment for systems by acquiring information of: Management structure The people Business activities Environmental systems The current information systems within organization * * System Analysis: Analysis of the present system Analyze HOW the present system.. Uses hardware Uses software Is networked Uses people resources to convert data resources into information products. How the IS activities of input, processing, output, storage, and control are accomplished. * * System Analysis: Functional requirements analysis What type of information does each business activity require? Format, volume, frequency, response times What are the information processing capabilities required? Input, processing, output, storage, control Finally, develop functional requirements Focusing on end user information requirements Goal – identify what should be done, not how to do it * * Analysis 2: Create Process Diagrams Process modeling – graphically representing the processes that capture, manipulate, store, and distribute information between a system and its environment Common process modeling diagrams include Data flow diagram (DFD) – illustrates the movement of information between external entities and the processes and data stores within the system Computer-aided software engineering (CASE) tools –automate systems analysis, design, and development * * Examples of CASE Tools Design Phase * * Phase 3: Design Design phase – involves describing the desired features and operations of the system including screen layouts, business rules, process diagrams, pseudo-code (i.e., high level principle of programming), and other documentation Primary design activities include: Design the IT infrastructure Design system models Generate alternative system designs, Compare alternatives, and Recommend best alternatives * * Design 1: Design the IT Infrastructure Organizations need a solid IT infrastructure to support their IT systems IT infrastructure must meet the organization’s needs in terms of time, cost, technical feasibility, and flexibility * * Design 2: Design System Models Modeling – the activity of drawing a graphical representation of a design Different modeling types include: Graphical user interface (GUI) – the interface to an information system GUI screen design – the ability to model the information system screens using icons, buttons, menus, and submenus Data models – a formal way to express data relationships to a database management system (DBMS) Entity relationship diagram (ERD) – a technique for documenting the relationships between entities in a database * Development & Testing Phases * * Phase 4: Development Development phase – involves taking all of the detailed design documents from the design phase and transforming them into the actual system Primary development activities include: Develop the IT infrastructure, which is the platform upon which the system will operate and must be built prior to building the actual system Develop the database and programs In the development phase, the organization purchases and implements the required equipment to support the IT infrastructure * * Phase 5: Testing Testing phase – involves bringing all the project pieces together into a special testing environment to test for errors, bugs, and interoperability, in order to verify that the system meets all the business requirements defined in the analysis phase Primary testing activities include: Write the test conditions-detailed steps the system must perform along with the expected results of each step Perform the system testing * Implementation Phase * * Phase 6: Implementation Implementation phase – involves placing the system into production so users can begin to perform actual business operations with the system Primary implementation activities include: Write detailed user documentation: highlights how to use the system Determine implementation method Provide training for the system users * * Implementation Activities of O’Brien & Maraks’s SDLC Model The Implementation stage of O’Brien (2011) includes the three phases of development, testing and implementation of Haag et al.’s model * * Conversion Methods Parallel Both old and new systems are operated until the project development team and end users agree to switch completely Phased Only