1什么是軟件項(xiàng)目管理.ppt

1、generic phases of software engineering,Layered Software Engineering,Software Process Models,Tools and techniques for process modeling: Static modeling(Lai notation) and dynamic modeling(system dynamics),Waterfall Model,Prototyping Model,Incremental Model,Spiral Model,Last class review,Tracking proje

2、ct progress Project personnel and organization Effort and schedule estimate Risk management Using process modeling with project planning,Chapter three Planning and Managing Projects,問(wèn)題 1.什么是軟件項(xiàng)目管理？ 2.軟件項(xiàng)目管理的內(nèi)容是什么？ 3.如果我是項(xiàng)目經(jīng)理，我應(yīng)該做什么 4.我可以勝任軟件項(xiàng)目管理嗎？,1995年SEI統(tǒng)計(jì)，美國(guó)共取消了810億美元的商業(yè)軟件項(xiàng)目，其中31的項(xiàng)目未做完就被取消，53的軟件項(xiàng)

3、目進(jìn)度通常要延長(zhǎng)50%的時(shí)間，只有9的軟件項(xiàng)目能夠及時(shí)交付并且費(fèi)用也控制在預(yù)算之內(nèi)。,2000年TechRepublic公司發(fā)表了有關(guān)IT項(xiàng)目的調(diào)查結(jié)果。該調(diào)查是以北美的1375個(gè)IT專(zhuān)家為對(duì)象實(shí)施問(wèn)卷調(diào)查進(jìn)行的。根據(jù)此調(diào)查，IT項(xiàng)目中有40%失敗，這些項(xiàng)目的平均成本每年花費(fèi)100萬(wàn)美元。,if a post mortem were to be conducted for every project,it is very likely that a consistent theme would be encountered:project management was weak,3.1 Tra

4、cking Progress,Usually, customers have several questions to be answered: Do you understand my problems and my needs? Can you design a system that will solve my problem or satisfy my needs? How long will it take you to develop such a system? How much will it cost to have you develop such a system?,A

5、Project Schedule describes the software development cycle for a particular project by enumerating the phases or stages of a project and breaking each into discrete tasks or activities to be done. The schedule also portrays the interactions among these activities and estimates the time that each task

6、 or activity will take.,Milestone: some events, and they indicate to us and our customers that a measurable level of progress has been made.,The distinguishing between activities and milestones: A activity is a part of the project that takes place over a period of time; A milestone is the completion

7、 of an activity and occurs at a particular point in time.,Work breakdown structure,Work Breakdown and Activity Graphs,The four parameters to describe each activity: A precursor: is an event or set of events that must occur before the activity can begin, it describes the set of conditions that allows

8、 the activity to begin. The duration: is the length of time needed to complete the activity. The due time: is the date by which the activity must be completed. The endpoint: is usually a milestone or deliverable, and represents the end of the activity. An activity graph: the nodes of the graph are t

9、he project milestones, and the lines linking nodes represent the activities involved.,Estimating Completion,Critical Path Method(CPM) The paths can show us the minimum amount of time it will take to complete the project, given our estimates of each activitys duration. CPM reveals those activities th

10、at are most critical to completing the project on time.,Slack time= available time real time Slack time= latest start time earliest start time,The critical path is the one for which the slack time at every node is zero. And it determines whether or not the project is on schedule.,The bar chart,Tools

11、 to Track Progress,Gantt Chart: a depiction of the project where the activities are shown in parallel, with the degree of completion indicated by a color or icon, the chart helps to understand which activities can be performed concurrently, and also to see which items are on the critical path.,Speci

12、fication approved,budget approved,schedule approved,plan approved,design approved,design approved,TODAY,3.3 Effort Estimation,The project budget pays for several types of costs: facilities, staff, methods, and tools,facilities,staff,methods,tools,Effort,Expert Judgment,Method 1: calculate the averag

13、e of estimates. Method 2: sit a meeting to make the experts agree on some estimate Method 3: Deiphi technology,Every expert estimates; Estimate in meeting; ai-the possibility of software minimal size mi-the most possibility of software size bi-the possibility of software maximal size Ei =(ai +4mi +

14、bi)/6 Discuss and estimate again in meeting Get an estimate with secrete ballot,Method 4: software cost matrix,A system,Old and Easy I/O module: 100 LOC New and Hard Algorithm module: 200 LOC Old and Medium Data management module: 100 LOC,Cost=(10017)+(200 35)+(100 31)=11800$,Algorithmic Methods,IBM

15、 model E=5.25S0.91 S is the estimated size of the system, E is the effort(PM). meta-model E=5.5+0.73S1.16 if R=(actual effort)E/(predicted effort)E then ERadj=,3. COCOMO (Constructive Cost Model),COCOMO estimation process reflects three major stages of any development project: Stage 1: projects buil

16、d prototypes to resolve high-risk issues involving user interfaces, software and interaction, performance, or technological maturity. COCOMO estimates size in application points. Stage 2: the early design stage, the designers must explore alternative architectures and concepts of operation. COCOMO e

17、stimates size in function points. Stage 3: the postarchitecture stage, sizing can be done in terms of function points or lines of code,.,The basic form of COCOMO: E=bScm(X) Where the initial size-based estimate bSc is adjusted by the vector of cost driver information m(X),Finding the Model for your

18、Situation two statistics to help you in assessing the accuracy: PRED: PRED(x/100) is the percentage of projects for which the estimate is within x%100 of the actual value. MMRE: is the mean magnitude of relative error.,3.4 Risk Management,What is risk? Risk pays more attention to the future events.

19、Risk relates to changing. Risk relates to choice and the uncertainty involved in choice., The characteristics of risk:, uncertainty The event that characterizes the risk may or may not happen; loss If the risk becomes a reality, unwanted losses will occur.,Distinguish risks from other project events

20、 by looking for three things: A loss associated with the event. The loss associated with a risk is called the risk impact. The likelihood that the event will occur. The likelihood of the risk, measured from 0 (impossible) to1 (certainty) id called the risk probability. When the risk probability is 1

21、, it is called a problem. The degree to which we can change the outcome. Risk control involves a set of actions taken to reduce or eliminate a risk.,Risk exposure = risk impact risk probability There are two major sources of risk: Generic risks: those common to all software projects, such as misunde

22、rstanding the requirements, losing key personnel, or allowing insufficient time for testing. Project-specific risks: threats that result from the particular vulnerabilities of the given project.,Risk Management Activities,risk impact risk probability = Risk exposure,The probability of an unwanted ou

23、tcome: P(UO) The loss associated with unwanted outcome:L(UO),There are three strategies for risk reduction: Avoiding the risk, by changing requirements for performance or functionality Transferring the risk, by allocating risks to other systems or by buying insurance to cover any financial loss shou

24、ld the risk become a reality Assuming the risk, by accepting it and controlling it with the projects resources,Risk leverage:,3.5 Project Plan,Project scope,Project schedule,Project team organization,Technical description of the proposed system,Project standards, procedures, and proposed techniques

25、and tools,Quality assurance plan,Configuration management plan,Documentation plan,Data management plan,Resource management plan,Test plan,Training plan,Security plan,Risk management plan,Maintenance plan,Review,The project schedule Work breakdown structure (phase-step-activity) An activity VS a mile

26、stone An activity graph The Critical Path Method Gantt chart,Project plan,Project personnel Effort estimation (Expert judgement and Algorithmic methods),項(xiàng) 目 管 理 案 例 分 析,1.整體性案例 Government Business Process Automation 2 專(zhuān)項(xiàng)討論案例 關(guān)于進(jìn)度問(wèn)題,Government Business Process Automation 某城市人民政府進(jìn)行機(jī)構(gòu)改革，新成立了一個(gè)部門(mén)城市管理辦公室

27、，負(fù)責(zé)城市水電、交通、環(huán)保、綠地等基礎(chǔ)設(shè)施以及城市應(yīng)急處理工作。為了使得新成立部門(mén)高效率運(yùn)轉(zhuǎn)，政府決定利用信息系統(tǒng)輔助該部門(mén)的日常業(yè)務(wù)。經(jīng)過(guò)商討，最終決定投資2500萬(wàn)元建立三套信息系統(tǒng)，一套是辦公自動(dòng)化系統(tǒng)，一套是數(shù)據(jù)采集與交換系統(tǒng)，一套是城市應(yīng)急指揮調(diào)度系統(tǒng)，三個(gè)系統(tǒng)作為一個(gè)項(xiàng)目進(jìn)行招標(biāo)，經(jīng)過(guò)激烈的競(jìng)爭(zhēng)，最終選取了在系統(tǒng)集成、MIS、GIS方面經(jīng)驗(yàn)豐富的A公司，項(xiàng)目建設(shè)周期為1年。 A公司經(jīng)討論確定成立一個(gè)由26人組成的項(xiàng)目開(kāi)發(fā)小組，并制訂了大致的開(kāi)發(fā)計(jì)劃如下： 1. 前期準(zhǔn)備工作 一周 2. 項(xiàng)目開(kāi)發(fā)工作 9個(gè)月 3. 系統(tǒng)試運(yùn)行 2個(gè)月 4. 系統(tǒng)驗(yàn)收 15天,請(qǐng)你試著回答以下一些問(wèn)題

28、： 1.你認(rèn)為9個(gè)月完成項(xiàng)目開(kāi)發(fā)有可能嗎，依據(jù)是什么,2.根據(jù)你對(duì)城市管理的了解和猜測(cè)，試著評(píng)估一下這個(gè)項(xiàng)目擁 有的資源。 3.請(qǐng)為該項(xiàng)目建立一個(gè)風(fēng)險(xiǎn)表。 4.選擇你熟悉的工具確定這個(gè)項(xiàng)目的生存周期和項(xiàng)目進(jìn)度表以及 人員分工組織。 5.為了確保項(xiàng)目質(zhì)量，請(qǐng)談一談如何進(jìn)行復(fù)審以及復(fù)審的時(shí)間、 內(nèi)容、方式。 6.請(qǐng)為該項(xiàng)目建一個(gè)配置管理庫(kù)。 7.制訂一份完整的軟件開(kāi)發(fā)計(jì)劃書(shū)，格式自定。,1.你認(rèn)為9個(gè)月完成項(xiàng)目開(kāi)發(fā)有可能嗎，依據(jù)是什么,合計(jì)：99451 功能點(diǎn)計(jì)算：99451 * (0.65 + 0.01 * (5+5+0+5+0+2+0+2+1+3+3+3+0+5) = 98456.49 按照以

29、往項(xiàng)目開(kāi)發(fā)經(jīng)驗(yàn)，每個(gè)人每月能夠完成的功能點(diǎn)數(shù)為450左右，則26個(gè)人9個(gè)月能夠完成功能點(diǎn)105300。,結(jié)論：9個(gè)月能夠完成項(xiàng)目，但是項(xiàng)目周期需要設(shè)計(jì)的比較緊湊（此外初期的功能點(diǎn)估算往往誤差較大，需要在設(shè)計(jì)階段修正）,2.根據(jù)你對(duì)城市管理的了解和猜測(cè)，試著評(píng)估一下這個(gè)項(xiàng)目擁 有的資源。,軟硬件環(huán)境方面：本項(xiàng)目資金充裕，可以購(gòu)置足夠的硬件和軟件工具，因此能夠保證硬件和軟件工具在項(xiàng)目開(kāi)發(fā)任何階段可用。 可復(fù)用組件方面：本項(xiàng)目無(wú)可以直接復(fù)用的軟件組件，完全需要自行開(kāi)發(fā) 人員方面：需要分解工作任務(wù)，建立工作任務(wù)之間的并行關(guān)系，并根據(jù)工作進(jìn)度詳細(xì)安排對(duì)人員組織進(jìn)行計(jì)劃,3.請(qǐng)為該項(xiàng)目建立一個(gè)風(fēng)險(xiǎn)表。,應(yīng)

30、建立類(lèi)似下表的風(fēng)險(xiǎn)評(píng)估單，責(zé)任人應(yīng)是明確的，并且不與其它資源發(fā)生沖突,4.選擇你熟悉的工具確定這個(gè)項(xiàng)目的生存周期和項(xiàng)目進(jìn)度表以及人員分工組織。,由于系統(tǒng)的復(fù)雜性和工作量，項(xiàng)目開(kāi)發(fā)采用風(fēng)險(xiǎn)最小的原型法，大致分成4個(gè)階段： 1.界面原型階段 以用戶界面為主設(shè)計(jì)原型，反復(fù)進(jìn)行直到用戶滿意，同時(shí)完成需求分析 2.設(shè)計(jì)原型階段 以系統(tǒng)結(jié)構(gòu)、模塊結(jié)構(gòu)為主設(shè)計(jì)原型，與用戶交流反映不同設(shè)計(jì)的比較，同時(shí)完成系統(tǒng)設(shè)計(jì) 3.功能原型階段 在原型基礎(chǔ)上實(shí)現(xiàn)系統(tǒng)功能，將原型變?yōu)楫a(chǎn)品 4.集成階段 將三個(gè)系統(tǒng)集成起來(lái) 根據(jù)這樣的進(jìn)度安排，項(xiàng)目定義了三個(gè)里程碑：界面里程碑（需求里程碑）；設(shè)計(jì)里程碑、集成里程碑（系統(tǒng)里程碑）

31、。下表為項(xiàng)目進(jìn)度甘特圖,按照這樣的進(jìn)度計(jì)劃，全體人員分成三個(gè)小組，即辦公自動(dòng)化小組、數(shù)據(jù)采集小組、應(yīng)急指揮小組，每個(gè)小組又細(xì)分成數(shù)據(jù)設(shè)計(jì)人員、服務(wù)設(shè)計(jì)人員、代理設(shè)計(jì)人員、客戶設(shè)計(jì)人員，每個(gè)小組設(shè)立兩個(gè)小組長(zhǎng)，一個(gè)負(fù)責(zé)技術(shù)協(xié)調(diào)，一個(gè)負(fù)責(zé)評(píng)審、質(zhì)證、風(fēng)險(xiǎn)控制、績(jī)效考核等管理工作,5.為了確保項(xiàng)目質(zhì)量，請(qǐng)談一談如何進(jìn)行復(fù)審以及復(fù)審的時(shí)間、 內(nèi)容、方式。,提供三種復(fù)審方式 小組內(nèi)部復(fù)審,在小組內(nèi)部進(jìn)行，需要提交復(fù)審報(bào)告，由小組長(zhǎng)組織 項(xiàng)目組復(fù)審，在項(xiàng)目組內(nèi)部進(jìn)行，需要提交復(fù)審報(bào)告，由項(xiàng)目經(jīng)理組織 外部復(fù)審，邀請(qǐng)客戶代表、技術(shù)經(jīng)理參加，需要提交正式的復(fù)審計(jì)劃書(shū)、復(fù)審會(huì)議紀(jì)要、復(fù)審意見(jiàn)表、復(fù)審報(bào)告，只有里

32、程碑和基線變更才需要進(jìn)行外部復(fù)審，由項(xiàng)目經(jīng)理組織,在項(xiàng)目進(jìn)行的不同階段，先后出現(xiàn)了一些異常情況，請(qǐng)根據(jù)情況回答問(wèn)題 .在項(xiàng)目進(jìn)行了1個(gè)月后，發(fā)現(xiàn)需求中要求實(shí)現(xiàn)與電力、交通、自來(lái)水等等十二個(gè)公司之間已經(jīng)建成的監(jiān)控系統(tǒng)之間進(jìn)行數(shù)據(jù)交換，這些系統(tǒng)具有不同的物理數(shù)據(jù)庫(kù)，不同的傳輸協(xié)議，不同的文件格式，在技術(shù)上存在很大的困難，這是原先沒(méi)有預(yù)計(jì)到的。 在項(xiàng)目進(jìn)行到4個(gè)月后，在質(zhì)量審計(jì)活動(dòng)中發(fā)現(xiàn)大部分項(xiàng)目都存在不同程度的質(zhì)量問(wèn)題，導(dǎo)致項(xiàng)目管理者處于矛盾之中：如果返工，則開(kāi)發(fā)進(jìn)度嚴(yán)重推延；但是如果繼續(xù)下去，可能導(dǎo)致最終產(chǎn)品不合格，從而需要更多的試運(yùn)行時(shí)間，最后進(jìn)度還是拖延 在項(xiàng)目進(jìn)行到6個(gè)月后，開(kāi)始出現(xiàn)開(kāi)發(fā)進(jìn)

33、度拖延問(wèn)題，6月初幾乎每一個(gè)計(jì)劃中任務(wù)都拖延半天到一天，到6月下旬計(jì)劃開(kāi)始拖延三天甚至一周 請(qǐng)仔細(xì)分析這三種情況，并分別制訂具體的行動(dòng)計(jì)劃,以上三種現(xiàn)象是軟件項(xiàng)目常見(jiàn)的問(wèn)題，即沒(méi)有預(yù)料的技術(shù)障礙、質(zhì)量問(wèn)題和進(jìn)度拖延。 對(duì)于第一個(gè)問(wèn)題，客觀原因是缺乏技術(shù)經(jīng)驗(yàn)，主觀原因是工作量度量和風(fēng)險(xiǎn)控制計(jì)劃不當(dāng)造成的，碰到這種情況，不僅需要進(jìn)行技術(shù)攻關(guān)，而且需要對(duì)原有項(xiàng)目開(kāi)發(fā)計(jì)劃的所有內(nèi)容重新進(jìn)行評(píng)估，看來(lái)拖延是不可避免的，這也是項(xiàng)目組最艱難的時(shí)期。 對(duì)于第二個(gè)問(wèn)題，導(dǎo)致的原因可能是多方面的（進(jìn)度太緊、獎(jiǎng)懲機(jī)制、管理者能力）。首先應(yīng)對(duì)整個(gè)項(xiàng)目組的生產(chǎn)率進(jìn)行評(píng)估，根據(jù)評(píng)估結(jié)論決定是否降低質(zhì)量標(biāo)準(zhǔn)，如果項(xiàng)目組的生產(chǎn)率完全適應(yīng)質(zhì)量計(jì)劃，則說(shuō)明人為因素導(dǎo)致質(zhì)量下降 對(duì)于第三個(gè)問(wèn)題，明顯是屬于進(jìn)度計(jì)劃和工作任務(wù)分解不合理造成的，主要是指在制訂計(jì)劃時(shí)忽略了最早完成和最晚完成之間的差，從而失去了控制進(jìn)度的余地，只有重新修正進(jìn)度和分解任務(wù)，使得并行程度更高，才能趕回進(jìn)度，否則拖延是不可避免的,進(jìn)度拖延了 XX公司是一家專(zhuān)門(mén)從事系統(tǒng)集成和應(yīng)用軟件開(kāi)發(fā)的公司，公司目前有員工50多人， 公司有銷(xiāo)售部、軟件開(kāi)發(fā)部、系統(tǒng)網(wǎng)絡(luò)部等業(yè)務(wù)部門(mén)，其中銷(xiāo)售部主要負(fù)責(zé)進(jìn)行公司服務(wù)和產(chǎn)