Cơ sở dữ liệu - Chapter 12: Implementing business/ it solutions

Chapter 12Implementing Business/IT SolutionsLearning ObjectivesUse the systems development process outlined in this chapter and the model of IS components from Chapter 1 as problem–solving frameworks to help you propose information systems solutions to simple business problems.Describe and give examples to illustrate how you might use each of the steps of the information systems development life cycle to develop and implement a buiness information system.Learning ObjectivesExplain how prototyping can be used as an effective technique to improve the process of systems development for end users and IS specialists.Understand the basics of project management and its importance to a successful systems development effort.Identify the activities involved in the implementation of new information systems.Learning ObjectivesCompare and Contrast the four basic information system conversion strategies.Describe several evaluation factors that should be considered in evaluating the acquisition of hardware, software, and IS services.Section 1Developing Business SystemsII. The Systems Approach Uses a systems orientation to defining and solving problems and opportunitiesProblem Solving – there are specific steps in solving any problemRecognize/Define a Problem or Opportunity – recognize it existsDevelop and Evaluate Alternative System Solutions – what are the different ways to solve this problem?Select the Best System Solution – decide which alternative is bestDesign the Selected System Solution – design the system for the chosen solutionImplement and Evaluate the Success of the Designed System – put the solution into effect and monitor results for the outcomeIV. Starting the Systems Development Process TheSystems Development Life CycleV. Systems Analysis A detailed study of the current system and organizational needsOrganizational Analysis – you must have a thorough understanding of the organization to make the system work wellAnalysis of the Present System – “those who fail to study history are doomed to repeat it”, a complete understanding of the current system is criticalLogical Analysis – create logical models the current system, WHAT the system does without regard to HOWFunctional Requirements Analysis and Determination – what Information is required for each business activity and what Processing is required in the systemVI. Systems DesignCreate a new system to solve the problem/opportunityPrototyping – create working models of the proposed systemThe Prototyping Process – prototypes are developed quickly for trial by users to obtain user feedbackUser Interface Design – critical because the interface is the part of the systems closest to the userSystem Specifications – listing of elements that formalize the designVI. Systems DesignThe Prototyping ProcessVII. Technical Note: Overview of Object- Oriented Analysis and DesignObjects – anything a programmer wants to manage or manipulateObject-Oriented Programming (OOP)Inheritance – ability to inherit properties of a higher-order objectModularity – a series of interlinked yet stand-alone modulesPolymorphism – different behavior based on conditionsEncapsulation – concealing all the properties inside the objectObject-Oriented Analysis (OOA) – modeling the problem domain as an object-oriented systemObject-Oriented Design (OOD) – create solutions using objectsSection 2Implementing Strategic Business SystemsIII. Project ManagementWhat Is a Project? – a set of activities with a beginning and an end, has goals and tasks, may have constraints (limitations)The Process of Project Management – five phases:Initiation and Defining – state the problem and identify objectives and resources, explore costs/benefitsPlanning – identify and sequence objectives/activitiesExecuting – put plans into motionControlling – ensure project objectives and deadlines are metClosing – install deliverables, release resources, end the projectV. Other Implementation ActivitiesTesting – testing and debugging are important, does the system work as it should?Data Conversion – new implementations often require replacing software and databasesDocumentation – an important means of communication, often overlookedTraining – training users is vital, usually under-budgeted, and expensiveV. Other Implementation ActivitiesPostimplementation Activities – Use and Maintenance – the longest and most costly phase of a system’s life; correct errors, improve performance, adapt to changes in the business environmentSystems Maintenance – making changes to the systemCorrective – fix errorsAdaptive – adding new functionalityPerfective – improve performancePreventative – reduce chances of future system failurePostimplementation Review – ensure the new system meets established business objectives