GIS工程讲义 第九讲GIS工程组织与管理工具.ppt

第九讲 GIS工程组织与管理工具SDEM90,Overview of SDEM90,This chapter introduces the basic concepts of FujitsuSDEM90(Systems Development Methodology Architecture)and briefly describes some of the individual project methodologies of which LPM(Large Project Methodology),11 Introduction to SDEM90,SDEM90 is an integrated approach to managing and developing all the information systems of a corporationIt can be used as a tool for common understanding by all parties，both internal and external to the corporation，who are involved in the management and development of the corporations information systems,SDEM90 comprises a strategic planning methodology，a number of system development methodologies and a system maintenance methodologyFigure 11 shows the integrated methodologies of SDEM90,Every methodology within SDEM90 is organized in a hierarchical structure of processes，activities and tasksThe SDEM90 model provides a pool of these processes，activities and tasks from which the component methodologies draw their own set,The component methodologies share the processes，activities，and tasks in the SDEM90 poolFor each methodology，a group of processes，activities and tasks are selected from the pool which are appropriate to that methodologyOne process，activity，or task from the pool may be used in any number of methodologies，For example，many project management processes and activities are common to all types of development methodologies such as waterfall，prototyping or re-engineeringThese processes and activities would then be included in each different methodology,Figure 12 represents the SDEM90 pool of processes，activities and tasks，and shows how several methodologies might use some of the same items from the pool,When the appropriate methodology has been selected for a particular project，the standard set of processes，activities and tasks for that methodology must be customized for that particular project，This customization procedure is dependent on the detailed project characteristicsAn overview of the customization procedure for LPM is provided in Section 212，Customizing LPM and details are provided in Chapter 3，Application of LPM,12SDEM90 Methodologies,121Strategic Planning MethodologyThe strategic planning methodology of SDEM90 analyzes the business situation，including the mission statements，policies and strategies of the corporation as a wholeThe objective of this methodology is to produce an Information Systems Development Plan ensuring that the development of computerized systems is in line with the business strategies of the corporation,122 System Maintenance Methodology,The system maintenance methodology focuses on the ongoing maintenance and enhancement of a corporations information systemAll aspects of the system require periodic maintenance including the operating system，program products，hardware，production application system and documentationThis methodology enables an integrated approach to the maintenance of the information system in line with the corporate strategies,123System Development Methodologies,SDEM90 comprises a number of system development methodologiesEach methodology is appropriate to a particular type of project,Large Project Methodology,LPM is one of the system development methodologies within SDEM90This methodology is best suited，but not strictly restricted to large development projects with the following characteristics：Involve new software developmentRequire an online systemRequire transaction processingHave a strong requirement for performance，reliability and operabilityRequire centralized developmentAre mission criticalHave a high risk factor,LPM uses the waterfall or cascade method of development which follows the traditional system development life cycleThis method requires planning，design，programming，testing and implementation stages of the project to be fully completed in a strict sequential orderFor example，the programming of a segment is completed before the testing of that segment commences，This method also enforces that testing of that segment commences，This method also enforces that once the programming of that segment is completed，no more programming activities are performed for that segment unless under strict change control procedures,Small Project MethodologySPM is a waterfall type of methodology similar to LPM and suitable for the same type of projects as LPM，but on a smaller scale,Prototyping MethodologyPrototyping is suited to projects which have a strong user commitment，a requirement for a short development timeframe and the availability of a Fourth Generation LanguageOne major characteristic of the prototyping methodology is the iterative nature of the processes,Introduction to LPMThis chapter introduces the basic LPM(Large Project Methodology)concepts and describes the benefits and components of the methodology.,2.1Overviews of LPM,LPM is a comprehensive methodology for analyzing,designing,and producing large scale Information Systems.The methodology follows the traditional system development life cycle form system planning through design,construction and testing to system implementation,evaluation and maintenance.All aspects of Information System production are contained in LPM,including the business,project management and system specification considerations as well as quality assurance,2.1.1Structure of LPM,Life Cycle PhaseLPM organizes the operations to be completed within the project into phase,The major phases include the traditional system development phases of Planning,Design,Construction,Testing,Implementation,Maintenance and System Evaluation.Each of these phases comprise one or more subphases,For example,the Testing phase includes the Program Test,Integration Test and System Test subphases.,LPM uses the waterfall of cascade method of development which requires each subphase of the project to be completed in a strict sequential order.For example the programming of a segment is completed before the testing of that segment commences,This method also enforces that once the programming of that segment is completed,no more programming activities are performed for that segment,except under strict change control procedures.,Categories of Operations The categories of operations within LPM enable the operations relating to the different aspects of the project to be grouped together.Categories are based on the business world,the computer world and the interface between the business and computer worlds,A further category is that of the operations relating to the actual management of the project.,The categories can be used for the assignment of team and/or individual responsibilities.For example,one team may be responsible for all tasks relating to the computer hardware.This team would then for all tasks relating to the computer hardware.This team would then be assigned the Hardware category.Depending on the size of the project,one team may be responsible for part of a category,one complete category or a number of categories.,Decomposition/Integration ProcedureA procedure of decomposition and integration is employed by LPM.This procedure breaks the system to be developed into small.manageable components,These components are then systematically rebuilt.The complete corporate model is broken down into the smallest system units of modules.These modules are then integrated to produce the completed system.,Work Breakdown Structure,The operations of the project are organized into an hierarchical structure,called the Work Breakdown Structure(WBS).This structure comprises three levels,from a high level overview to a detailed level showing the milestones and deliverables produced.,the hierarchical nature of LPM enables the entire project to be viewed in levels.Each level has a different purpose and is used in a different manner.The first level shows the overall organization of the project and is a tool for management.The second level enables resources,such as,time,personnel,techniques,tools,and materials,to be assessed and assigned.The third level details the actual work which to be completed and the output produced from this work.,The operations described by the first or highest level are defined as the WBS Level 1 Processes,or simply Processes.The second level operations are defined as the WBS Level 2 Activities,or Activities,and the final level,or lowest level,operations are defined as the WBS Level 3 Tasks,or Tasks.,Each level is a decomposition of the higher level operation into one or more detailed operations.For example,the first level provides an overview of a process.The second level may decompose this one process into two activities each described in more detail than the higher level process.Each of these two activities may then be broken down into a number of tasks,all of which are described in the finest detail.,Figure 2.3 shows the structure of the processes,activities,and tasks the Work Breakdown Structure.This manual gives an overview of the WBS and detailed descriptions of the processes,activities and tasks are contained in the LPM WBS Reference Manual.,Deliverables of LPM,LPM places major importance on the deliverables produced throughout the development project.The deliverables facilitate communication among the personnel involved directly in the development project and with personnel external to the project.Both the contents and types of documents produced have a great influence on the quality of the system produced and on the productivity of the project.,The methodology organizes the project deliverables into a structure similar to the hierarchical WBS.There are three levels of deliverables.The highest level comprises the File System.The Report System is the second level and the third level contains the individual Documents.,As with the WBS,each level of deliverables comprises more detailed components of the higher level.For example,a File exists in the highest level.This File may contain a number of Reports which correspond to the second level.Each report may comprise numerous individual Documents which correspond to the lowest level of deliverables.,Figure 2.4 shows the three level structure of the deliverables of LPM.,The organization of the processes,activities,and tasks is in a matrix of phases and categories.LPM organizes the deliverables in a similar manner.Figure 2.5 shows the relationship between the phases,categories,and deliverables in LPM.,The combined organization of tasks and deliverables into phases and categories results in a structured methodology which is easily understood.Each project participant need only concentrate on the tasks and deliverables in the category or categories relevant to them and on the current phases of the project.,2.1.2Customizing LPM,As described earlier in this chapter,LPM is a methodology comprising a comprehensive set of processes,activities,and tasks.The candidate projects for development using this methodology have similar basic characteristics.All would be of a large scale,with strong requirementsfor performance,reliability,and operability and all would be best suited to the waterfall approach of development used by LPM.,The projects which fall into this generalized classification may havemore specific characteristics that require LPM to be customized for them.The comprehensive nature of the set of processes,activities,and tasks comprising LPM typically results in the methodology requiring some amount of customization for each project.,2.2 Benefits of LPM,As an integral pan of SDEM90,LPM provides a methodology consistent with the overall system development architecture of a corporation.The structure and organization of LPM provides several benefits,such as:,All critical tasks and deliverables are included in the methodologyA more accurate estimation of the cost and time required to complete the project is achievableA development environment is created which enables high productivityQuality control is introduced into the development cycle results in the production of high quality products.Prevents Critical Omissions,Introduction to the Phases of LPM This section describes the major phases into which the processes,activities and tasks of LPM are organized.The phases follow the traditional systems development life phases:1 The Planning phase 2 The Design phase 3 The Construction phase 4 The Testing phase 5 Implementation,2.3.1The Planning Phase,The first phase of the methodology is the Planning phase.In this phase,the project focuses mainly on the business aspects of the corporation,initially looking at the entire company and then breaking the company into separate business areas.The proposed systems are established and analyzed to determine the requirements,scope and duration of each development project.,The Planning phase comprisestwo subphases:The System Planning subphaseThe Systems Analysis subphase,The System Planning Subphase,The activities of the System Planning subphase focus on two major areas of the project.1.overall corporate environment 2.the planning of the project.The corporate environment comprises all aspects of the company,including business and information systems practices.The project planning completed during this subphase is not specific to LPM,but includes standard activities which should be completed before any project is commenced,regardless of the methodology used.,The System Planning subphase may be completed as part of the overall project or it may be a separate exercise,completed discretely before any development project is considered.The same activities are performed in each case.In this manual,it is classed as an integral part of the overall methodology.,The Systems Analysis Subphase,This subphase continues the focus on the business aspects of the corporation from the System Planning subphase.The present situation and future requirements of the company are further investigated,but at the business area level rather than the overall corporate level.,2.3.2The Design Phase,The Design phase focuses on the transformation of the business aspectsinto the computer world.The business area requirements are convened into system specifications which are used to design,code and test the system throughout the project.,The Design phase consists of three subphases:The User Interface Design subphase The System Structure Design subphase The Program Structure Design subphase,The User Interface Design Subphase,This is the first of the design subphases.The planning has been completed and the decision has been made to develop a system.The major output of the User Interface Design subphase is the design specifications for all aspects of the system.These specifications are the transformation of the user requirements,written in business language,into the system design,written in computer language.,The system specifications include the system function,performance,security,operability,data structure and conversion specifications.The user requirements,which were determined in the previous subphase are analyzed.All requirements that are b