1、精選優質文檔-傾情為你奉上NET-BASED TASK MANAGEMENT SYSTEMHector Garcia-Molina, Jeffrey D. Ullman, Jennifer WisdomABSTRACTIn net-based collaborative design environment, design resources become more and more varied and complex. Besides common information management systems, design resources can be organized in co

2、nnection with design activities.A set of activities and resources linked by logic relations can form a task. A task has at least one objective and can be broken down into smaller ones. So a design project can be separated into many subtasks forming a hierarchical structure.Task Management System (TM

3、S) is designed to break down these tasks and assign certain resources to its task nodesAs a result of decomposition.al1 design resources and activities could be managed via this system.KEY WORDS：Collaborative Design, Task Management System (TMS), Task Decomposition, Information Management System1 In

4、troductionAlong with the rapid upgrade of request for advanced design methods, more and more design tool appeared to support new design methods and forms. Design in a web environment with multi-partners being involved requires a more powerful and efficient management system .Design partners can be l

5、ocated everywhere over the net with their own organizations. They could be mutually independent experts or teams of tens of employees. This article discusses a task management system (TMS) which manages design activities and resources by breaking down design objectives and re-organizing design resou

6、rces in connection with the activities. Comparing with common information management systems (IMS) like product data management system and document management system, TMS can manage the whole design process. It has two tiers which make it much more f1exible in structure.The 1ower tier consists of tr

7、aditional common IMSS and the upper one fulfills logic activity management through controlling a tree-like structure, allocating design resources and making decisions about how to carry out a design project. Its functioning paradigm varies in different projects depending on the projects scale and pu

8、rpose. As a result of this structure, TMS can separate its data model from its logic mode1.It could bring about structure optimization and efficiency improvement, especially in a large scale project.2 Task Management in Net-Based Collaborative Design Environment2.1 Evolution of the Design Environmen

9、tDuring a net-based collaborative design process, designers transform their working environment from a single PC desktop to LAN, and even extend to WAN. Each design partner can be a single expert or a combination of many teams of several subjects, even if they are far away from each other geographic

10、ally. In the net-based collaborative design environment, people from every terminal of the net can exchange their information interactively with each other and send data to authorized roles via their design tools. The Co Design Space is such an environment which provides a set of these tools to help

11、 design partners communicate and obtain design information. Code sign Space aims at improving the efficiency of collaborative work, making enterprises increase its sensitivity to markets and optimize the configuration of resource.2.2 Management of Resources and Activities in Net-Based Collaborative

12、EnvironmentThe expansion of design environment also caused a new problem of how to organize the resources and design activities in that environment. As the number of design partners increases, resources also increase in direct proportion. But relations between resources increase in square ratio. To

13、organize these resources and their relations needs an integrated management system which can recognize them and provide to designers in case of they are needed.One solution is to use special information management system (IMS).An IMS can provide database, file systems and in/out interfaces to manage

14、 a given resource. For example there are several IMS tools in Co Design Space such as Product Data Management System, Document Management System and so on. These systems can provide its special information which design users want.But the structure of design activities is much more complicated than t

15、hese IM S could manage, because even a simple design project may involve different design resources such as documents, drafts and equipments. Not only product data or documents, design activities also need the support of organizations in design processes. This article puts forward a new design syste

16、m which attempts to integrate different resources into the related design activities. That is task management system (TMS).3 Task Breakdown Model3.1 Basis of Task BreakdownWhen people set out to accomplish a project, they usually separate it into a sequence of tasks and finish them one by one. Each

17、design project can be regarded as an aggregate of activities, roles and data. Here we define a task as a set of activities and resources and also having at least one objective. Because large tasks can be separated into small ones, if we separate a project target into several lowerlevel objectives, w

18、e define that the project is broken down into subtasks and each objective maps to a subtask. Obviously if each subtask is accomplished, the project is surely finished. So TMS integrates design activities and resources through planning these tasks.Net-based collaborative design mostly aims at product

19、s development. Project managers (PM) assign subtasks to designers or design teams who may locate in other cities. The designers and teams execute their own tasks under the constraints which are defined by the PM and negotiated with each other via the collaborative design environment. So the designer

20、s and teams are independent collaborative partners and have incompact coupling relationships. They are driven together only by theft design tasks. After the PM have finished decomposing the project, each designer or team leader who has been assigned with a subtask become a 1ow-class PM of his own ta

21、sk. And he can do the same thing as his PM done to him, re-breaking down and re-assigning tasks.So we put forward two rules for Task Breakdown in a net-based environment, incompact coupling and object-driven. Incompact coupling means the less relationship between two tasks. When two subtasks were co

22、upled too tightly, the requirement for communication between their designers will increase a lot. Too much communication wil1 not only waste time and reduce efficiency, but also bring errors. It will become much more difficult to manage project process than usually in this situation. On the other ha

23、nd every task has its own objective. From the view point of PM of a superior task each subtask could be a black box and how to execute these subtasks is unknown. The PM concerns only the results and constraints of these subtasks, and may never concern what will happen inside it.3.2 Task Breakdown Me

24、thodAccording to the above basis, a project can be separated into several subtasks. And when this separating continues, it will finally be decomposed into a task tree. Except the root of the tree is a project, all eaves and branches are subtasks. Since a design project can be separated into a task t

25、ree, all its resources can be added to it depending on their relationship. For example, a Small-Sized-Satellite.Design (3SD) project can be broken down into two design objectives as Satellite Hardware. Design (SHD) and Satellite-Software-Exploit (SSE). And it also has two teams. Design team A and de

26、sign team B which we regard as design resources. When A is assigned to SSE and B to SHD. We break down the project as shown in Fig 1.It is alike to manage other resources in a project in this way. So when we define a collaborative design projects task model, we should first claim the projects target

27、s. These targets include functional goals, performance goals, and quality goals and so on. Then we could confirm how to execute this project. Next we can go on to break down it. The project can be separated into two or more subtasks since there are at 1east two partners in a collaborative project. E

28、ither we could separate the project into stepwise tasks, which have time sequence relationships in case of some more complex projects and then break down the stepwise tasks according to their phase-to-phase goals.There is also another trouble in executing a task breakdown. When a task is broken into

29、 severa1 subtasks; it is not merely “a simple sum motion” of other tasks. In most cases their subtasks could have more complex relations.To solve this problem we use constraints. There are time sequence constraint (TSC) and logic constraint (LC). The time sequence constraint defines the time relatio

30、nships among subtasks. The TSC has four different types, FF, FS, SF and SS. F means finish and S presents start. If we say Tabb is FS and lag four days, it means Tb should start no later than four days after Ta is finished.The logic constraint is much more complicated. It defines logic relationship

31、among multiple tasks.Here is given an example:“Task TA is separated into three subtasks, Ta, T b and Tc. But there are two more rules.Tb and Tc can not be executed until Ta is finished.Tb and Tc can not be executed both，that means if Tb was executed, Tc should not be executed, and vice versa. This d

32、epends on the result of Ta.”So we say Tb and Tc have a logic constraint. After finishing breaking down the tasks, we can get a task tree as Fig, 2 illustrates.4 TMS Realization4.1 TMS StructureAccording to our discussion about task tree model and task breakdown basis, we can develop a Task Managemen

33、t System (TMS) based on Co Design Space using Java language, JSP technology and Microsoft SQL 2000. The task management systems structure is shown in Fig. 3.TMS has four main modules namely Task Breakdown, Role Management, Statistics and Query and Data Integration. The Task Breakdown module helps us

34、ers to work out task tree. Role Management module performs authentication and authorization of access control. Statistics and Query module is an extra tool for users to find more information about their task. The last Data Integration Module provides in/out interface for TMS with its peripheral envi

35、ronment.4.2 Key Points in System Realization4.2.1 Integration with Co Design SpaceCo Design Space is an integrated information management system which stores, shares and processes design data and provides a series of tools to support users. These tools can share all information in the database becau

36、se they have a universal Data Mode1. Which is defined in an XML (extensible Markup Language) file, and has a hierarchical structure. Based on this XML structure the TMS h data mode1 definition is organized as following.<?xml version= 1.0 encoding= UTF-8?><!-comment：Common Resource Definitio

37、ns AboveThe Followingare Task Design-><!ELEMENT ProductProcessResource (Prcses?, History?，AsBuiltProduct*，ItemsObj?, Changes?, ManufacturerParts?， SupplierParts?，AttachmentsObj? ， Contacts?， PartLibrary?，AdditionalAttributes*)><!ELEMENT Prcses (Prcs+) ><!ELEMENT Prcs (Prcses， PrcsN

38、otes?， PrcsArc*，Contacts?，AdditionalAttributes*，Attachments?)><!ELEM ENT PrcsArc EMPTY><!ELEMENT PrcsNotes(PrcsNote*)><!ELEMENT PrcsNote EMPTY>Notes: Element “Pros” is a task node object, and “Process” is a task set object which contains subtask objects and is belongs to a highe

39、r class task object. One task object can have no more than one “Presses” objects. According to this definition, “Prcs” objects are organized in a tree-formation process. The other objects are resources, such as task link object (“Presage”), task notes (“Pros Notes”), and task documents (“Attachments

40、”) .These resources are shared in Co Design database.文章出處：計算機智能研究J,47卷，2007：647-703專心-專注-專業基于網絡的任務管理系統摘 要在網絡與設計協同化的環境下，設計資源變得越來越多樣化和復雜化。隨著信息管理系統的普及，設計資源在各種設計活動的相互聯系過程中被迅速組織起來。一整套在邏輯關系中聯接的活動和資源可以組成一個任務。一個任務至少有一個對象，并且可被拆分為很多小的子任務。所以設計項目可分為許多子任務，并由它們形成一個嚴謹的層次結構。任務管理系統（TMS）是被設計來打破這些任務，并指定某些資源去協調其相關工作。這樣

41、做的結果就是所有的設計資源和活動都通過這個系統被管理起來。關鍵詞：協同設計，任務管理系統（TMS），任務分解，信息管理系統1 簡介隨著對先進設計方法的要求的不斷提高，支持新的設計方法和形式的設計工具不斷涌現。在網絡環境下多伙伴參與的設計活動，需要一個更強大和有效率的管理系統。設計伙伴可以在任何地點鎖定自己的組織，它們可以讓專家或團隊數千員工相互獨立起來。本文論述了一種通過打破并重組設計資源與活動來管理設計和活動資源的任務管理系統（TMS）。與普通信息管理系統(IMS)比較，例如產品數據管理系統和文件管理系統，任務管理系統能夠管理整個設計過程。它的雙層結構使之結構更加靈活。底層由傳統的普通信息管

42、理系統結構（IMSS）組成，而高層通過控制樹形結構來實現邏輯活動的管理，配置資源以及就如何開展設計項目展開設計和決策。其運作模式也會根據項目的規模和目的產生變化。正是由于這種結構，任務管理系統可以把它的數據模型從其邏輯模型中分離出來，這樣將會帶來結構優化和效益改善，尤其對一個大型項目來說，作用更加明顯。2 基于網絡的任務管理系統開發環境2.1 設計環境的演進在網絡化協同設計過程中，設計師不斷變換著自己的工作環境，從個人電腦到局域網等,甚至延伸至廣域網。每個設計伙伴，可以是一個單獨專家或結合許多項目的幾個科研小組，即使在地理位置上相距遙遠。在這樣網絡化協同設計環境中，來自不同網絡終端的人們都可以

43、通過協同的設計空間互動的互相交流信息和發送數據。這種環境提供了一整套工具來幫助設計伙伴溝通和獲取設計資料。協同空間旨在提高效率的協同工作，使企業增加敏感的市場,優化配置資源。2.2 在互動的網絡環境下對資源和活動的管理設計環境的擴展同樣造成了一系列新的問題，比如在這種環境下怎么樣組織資源和活動。隨著設計伙伴數量的不斷增加。資源也在成比例的不斷增加著。但是不同資源之間的聯系也在不斷的隨著它們的增加而不斷提高。如何組織資源間的聯系就需要一個綜合的管理系統，一個可以組織它們并在各種條件下將其提供給那些需要它的設計師的管理系統。一個解決方法是使用特殊的信息管理系統（IMS）。這種信息管理系統能夠提供數

44、據庫,文件系統和輸入/輸出接口來管理已知的資源。舉個例子，在工作空間中有各種不同的ISM工具，如產品數據管理系統文件管理系統等。這些系統可以給他們的用戶提供他們需要的各種特殊的信息。但是結構的設計活動是一項比IMS所能管理的極限還要復雜的多的活動，因為即使一個簡單的設計工作可能也需要處理不同的設計資源比如說文件、匯票和各種設備。不僅僅只有產品的數據或者文件，設計活動同樣也需要設計過程所提供的各種組織過程。這篇文章提出了一種新的設計系統，它試圖把不同的設計資源放進相關的設計活動中，這個就是任務管理系統（TMS）。3 任務分解模型3.1 任務分解的依據當人們去完成一個項目時，他們通常會先把它分解成

45、一個個的小任務，然后再去一個個的完成它。每個設計的項目都可以看作是一個整體的活動，各種對象和數據。我們定義的這個任務同樣也需要一系列的活動和資源，并最少擁有一個活動。因為大的任務可以被分解成小的任務，如果我們將一個項目目標分解成幾個低級別的目標，我們定義了將這個項目分解成不同的子任務同時每個目標也都映射到一個子任務。顯然，如果每個子任務都完成，這個項目肯定已經被完成掉，所以TMS根據這些任務規劃了資源和活動的分配。大多數的網絡化協同設計都將他們的目標定在產品的發展上。項目的管理者將這些子任務交給設計師或者設計團隊。這些設計師或者團隊在項目主管指定的條件下進行他們各自任務的設計。所以這些設計師和

46、設計團隊是相互獨立的伙伴并且組織松散。當項目主管完成對這些項目的分解時，每個設計師或者設計團隊的領隊都會被指派一個已經低級別的子任務，并且他們可以做和他們主管同樣的事，將這些子任務打破并且重新分配給他的設計師或者團隊。因此，在網絡環境下我們為任務分解提出了兩項規則，松散的組合和有目的的項目。松散的組合指得是兩項任務之間的聯系很少，當兩個子任務被捆綁的很緊的話，它們的設計者之間的通信量將會增加很多。大量的通信只會浪費時間和降低效率，與此同時也會帶來錯誤。管理項目的過程也會變得比平常更加的困難。另一方面，每個任務都有它自己的工作對象。從項目主管的角度來看，每個子任務都是未知的。他們的注意力只會放在

47、結果和這些子任務的內容上，并且可能永遠都不會關心這個小黑匣子里面會發生什么。3.2 任務分解模式根據上面的基礎,一個項目能被分解為一些子任務，并且當這些分解繼續進行時，它最終會組成一個任務樹。除非樹的結點是一個項目，所有其他的樹葉和樹枝都是一個個子任務，正是由于一個設計項目可以被分解成一個任務樹，所有這些資源都能根據它們之間的關系被添加到適當的位置上，舉個例子來說，一個小型的衛星。設計項目可以像衛星一樣被分解成2個設計項目。硬件，設計和軟件。并且他也可以有2個團隊，設計團隊A和設計團隊B，這些我們都可以把他們看作設計資源，當A被映射到SSE，B映射到SHD時，我們就像圖1一樣將這個項目分解掉。管理一個項目中的其他資源用的也是這種方法，所以當我們確定了一個設計項目的任務模型時，我們應該首先搞清楚這個項目的目的。這些目標包括系統的目的，業績的目標，質量的目標等等。然后我們應該確定如何執行這個項目，緊接著我們可以開始將它細化。因為有最少2個的設計伙伴，這些項目可以被分解成一個或者更多的子任務?；蛘弋斘覀冇龅揭恍└鼜碗s的項目時