Work Breakdown Structure (WBS)
| Line 7: | Line 7: | ||
==History== | ==History== | ||
| − | The WBS was initially developed by the U.S. defense, back to the 1950’s and 60’s, in cooperation with NASA they were adopting the Program Evaluation and Review Technique (PERT) <ref>S1 Cleland, David I. and Roland Gareis, Global Project Management Handbook, McGraw Hill Professional, 2006</ref> . During 1962, United State Airforce released “STUDY OF METHODS FOR EVALUATION OF THE PERT/COST MANAGEMENT SYSTEM” in this document was mention WBS as a useful tool for Controlling and planning large acquisition projects <ref> Eric S. Norman, Shelly A. Brotherton, Robert T. Fried Work Breakdown Structures: The Foundation for Project Management Excellence, Wiley, 2010</ref> . As understandable, most of NASA projects involves many actors (contractors) with totally different | + | The WBS was initially developed by the U.S. defense, back to the 1950’s and 60’s, in cooperation with NASA they were adopting the Program Evaluation and Review Technique (PERT) <ref>S1 Cleland, David I. and Roland Gareis, Global Project Management Handbook, McGraw Hill Professional, 2006</ref> . During 1962, United State Airforce released “STUDY OF METHODS FOR EVALUATION OF THE PERT/COST MANAGEMENT SYSTEM” in this document was mention WBS as a useful tool for Controlling and planning large acquisition projects <ref> Eric S. Norman, Shelly A. Brotherton, Robert T. Fried Work Breakdown Structures: The Foundation for Project Management Excellence, Wiley, 2010</ref> . As understandable, most of NASA projects involves many actors (contractors) with totally different tasks. However, all of them are parts of the same project and works for the same final scope. The WBS was used to ‘‘ . . . ensure that the total project is fully planned and that all derivative plans contribute directly to the desired objectives’’ (NASA, 1962)<ref>"Background and Key Concepts COPYRIGHTED MATERIAL." Web. 20 Sep. 2015</ref>. After, this first approach NASA decide to keep update this document because believed valid and useful. In 1968, due to its success, the Department of Defense released "Work Breakdown Structures for Defense Materiel Items" (MIL-STD-881), a military standard procedure which is obligatory for all programs under the Department of Defense. This standard is constantly updated, the latest version refers tp 2001 <ref>''[http://www.mcri.com/wp-content/uploads/2014/09/Military-Standard-881C-----Department-of-Defense-Standard-Practice-----Work-Breakdown-Structures-for-Defense-Materiel-Items-MIL-STD-881C-3-Oct-11.pdf Military-Standard-881C]'', 3 October 2011</ref>. |
| − | Project Management Institute (PMI) during 1987 started to enlarge these collections of documents for non-military purpose as result The Project Management Body of Knowledge (PMBOK) has been release. The first version is from 1987, and other versions have been released during (987, 1996, 2000, 2004, 2009, 2013 | + | Project Management Institute (PMI) during 1987 started to enlarge these collections of documents for non-military purpose as result The Project Management Body of Knowledge (PMBOK) has been release. The first version is from 1987, and other versions have been released during (987, 1996, 2000, 2004, 2009, 2013 <ref>"Guide, A. "Project Management Body of Knowledge (PMBOK® GUIDE & STANDARD)." Project Management Institute. 2001.</ref>. The main concept of subdividing different activities through different levels remain the same of the early years. However, the approach goes from “A task- oriented ‘family tree’ of activities 1987” PMBOKfirst Guide to “A deliverable- oriented hierarchical decomposition of the work to be executed by the project team to accomplish the project objectives and create the required deliverables” (PMBOK Guide — Third). |
On one hand, the documents from PMI gives an overview of the WBS concept, on the other hand, the document released from the Department of Defense can be considered as a Handbook. | On one hand, the documents from PMI gives an overview of the WBS concept, on the other hand, the document released from the Department of Defense can be considered as a Handbook. | ||
| + | ==Representation== | ||
| + | As mentioned before the aim of a WBS is to show at best the scope of the project, program or portfolio taken into consideration. There is no one exact or mandatory way of representing a WBS. Nevertheless, all of them have in common a tree structure. The most use tree structure is the one called inverted Tree Structure Picture 2, in this representation the project has the aspect of an organization chart. However there are other two types of representation the one shown In !!!!picture!!! that has the root on the left side and growth from the right side, the last one is called centralized tree structure Picture this can help the development session. | ||
| + | |||
| + | The graphical representation is not the only way of representing a WBS, tabular views are also used. This approach has the advantage to be clearer in case the WBS has many levels an example is shown in figure !!!Picture!!!. Usually at top level is shown the main deliverable that can change depending what kind of project is analyzed .Lower level provide information to the project managers like, schedule development, cost estimating, resource allocation, and risk assessment. The lowest level also called Work Packages. it is defined by PMI as :” A deliverable or project work component at the lowest level of the Work Breakdown Structure. The work package includes the schedule activities and schedule milestones required to complete the work package deliverable or project work component’.It is a good habit as suggest NASA of not having more than 7 levels . Each element of a WBS is recognasible by a clear, descriptive title and by a numbering scheme | ||
| + | |||
| + | Depending on the level the management might assign responsibility for technical, schedule, and cost performance. A Control Account is usually established to guaranty at best he intersection between of WBS element and organization unit. | ||
| + | |||
| + | ==100% Rule== | ||
| + | |||
| + | |||
| + | One of the most important principles for developing a WBS is called 100% rule. This rule is define from Project Management Institute (PMI). | ||
| + | |||
| + | This 100% rule define that a WBS must Include the 100% of the work defined from the project and include all the necessary for its realization (Internal, contractor, subcontractor) included the management of the project itself. The 100% rule is one of the most important guideline for developing the decomposition and evaluation of a WBS. The rule is applied at all levels of the hierarchical structure : ‘the next level of decomposition of a WBS element (child level) must represent 100 percent of the work applicable to the next higher (parent) element’’ <ref> Haugan, Gregory T. 2002. Effective Work Breakdown Structures. Vienna, VA Management Concepts</ref> (Haugan p. 17).. | ||
| + | The WBS can not include jobs out of the project’s border , meaning that should not include more of the 100%. | ||
| + | |||
| + | Applying the 100% Rule allows the manager to know that all efforts in each area are captured where they belong and also that nothing unrelated is included in an element. Application of the 100% Rule enables all outcomes to be defined before schedule planning begins. The work breakdown structure is the initiator in the planning process, as planned outcomes must be defined before methods and schedules can be considered. If outcomes are insufficiently defined, the project cannot succeed. Awareness of the 100% Rule enables and communicates full understanding of all necessary outcomes. Once the project is underway the 100% Rule assists in assuring that project costs are properly shown in the accounting system. This is true for all projects, whether they are accomplished for another division in a company or for a regular paying customer. Application of the 100% Rule enables accurate costing, which is essential to budgeting similar efforts in the future. | ||
==References== | ==References== | ||
<references/> | <references/> | ||
Revision as of 20:24, 20 September 2015
Work Breakdown Structure (WBS) is a tool used in project management context that divide in different levels of details a deliverable-oriented project in hierarchical order. The main objective is to support the project manager by giving an overview of different steps, resources and costs involved in the project. Moreover during the project executions may include the percentage of steps completed this ensure better control and guidance in case during the project development may occur any changes. It is graphically represented by a hierarchical tree, where the job of each element is given by the sum of elements underneath connected (sublevels). These elements may represent a product, data, service or any combination thereof.
Contents |
History
The WBS was initially developed by the U.S. defense, back to the 1950’s and 60’s, in cooperation with NASA they were adopting the Program Evaluation and Review Technique (PERT) [1] . During 1962, United State Airforce released “STUDY OF METHODS FOR EVALUATION OF THE PERT/COST MANAGEMENT SYSTEM” in this document was mention WBS as a useful tool for Controlling and planning large acquisition projects [2] . As understandable, most of NASA projects involves many actors (contractors) with totally different tasks. However, all of them are parts of the same project and works for the same final scope. The WBS was used to ‘‘ . . . ensure that the total project is fully planned and that all derivative plans contribute directly to the desired objectives’’ (NASA, 1962)[3]. After, this first approach NASA decide to keep update this document because believed valid and useful. In 1968, due to its success, the Department of Defense released "Work Breakdown Structures for Defense Materiel Items" (MIL-STD-881), a military standard procedure which is obligatory for all programs under the Department of Defense. This standard is constantly updated, the latest version refers tp 2001 [4]. Project Management Institute (PMI) during 1987 started to enlarge these collections of documents for non-military purpose as result The Project Management Body of Knowledge (PMBOK) has been release. The first version is from 1987, and other versions have been released during (987, 1996, 2000, 2004, 2009, 2013 [5]. The main concept of subdividing different activities through different levels remain the same of the early years. However, the approach goes from “A task- oriented ‘family tree’ of activities 1987” PMBOKfirst Guide to “A deliverable- oriented hierarchical decomposition of the work to be executed by the project team to accomplish the project objectives and create the required deliverables” (PMBOK Guide — Third).
On one hand, the documents from PMI gives an overview of the WBS concept, on the other hand, the document released from the Department of Defense can be considered as a Handbook.
Representation
As mentioned before the aim of a WBS is to show at best the scope of the project, program or portfolio taken into consideration. There is no one exact or mandatory way of representing a WBS. Nevertheless, all of them have in common a tree structure. The most use tree structure is the one called inverted Tree Structure Picture 2, in this representation the project has the aspect of an organization chart. However there are other two types of representation the one shown In !!!!picture!!! that has the root on the left side and growth from the right side, the last one is called centralized tree structure Picture this can help the development session.
The graphical representation is not the only way of representing a WBS, tabular views are also used. This approach has the advantage to be clearer in case the WBS has many levels an example is shown in figure !!!Picture!!!. Usually at top level is shown the main deliverable that can change depending what kind of project is analyzed .Lower level provide information to the project managers like, schedule development, cost estimating, resource allocation, and risk assessment. The lowest level also called Work Packages. it is defined by PMI as :” A deliverable or project work component at the lowest level of the Work Breakdown Structure. The work package includes the schedule activities and schedule milestones required to complete the work package deliverable or project work component’.It is a good habit as suggest NASA of not having more than 7 levels . Each element of a WBS is recognasible by a clear, descriptive title and by a numbering scheme
Depending on the level the management might assign responsibility for technical, schedule, and cost performance. A Control Account is usually established to guaranty at best he intersection between of WBS element and organization unit.
100% Rule
One of the most important principles for developing a WBS is called 100% rule. This rule is define from Project Management Institute (PMI).
This 100% rule define that a WBS must Include the 100% of the work defined from the project and include all the necessary for its realization (Internal, contractor, subcontractor) included the management of the project itself. The 100% rule is one of the most important guideline for developing the decomposition and evaluation of a WBS. The rule is applied at all levels of the hierarchical structure : ‘the next level of decomposition of a WBS element (child level) must represent 100 percent of the work applicable to the next higher (parent) element’’ [6] (Haugan p. 17).. The WBS can not include jobs out of the project’s border , meaning that should not include more of the 100%.
Applying the 100% Rule allows the manager to know that all efforts in each area are captured where they belong and also that nothing unrelated is included in an element. Application of the 100% Rule enables all outcomes to be defined before schedule planning begins. The work breakdown structure is the initiator in the planning process, as planned outcomes must be defined before methods and schedules can be considered. If outcomes are insufficiently defined, the project cannot succeed. Awareness of the 100% Rule enables and communicates full understanding of all necessary outcomes. Once the project is underway the 100% Rule assists in assuring that project costs are properly shown in the accounting system. This is true for all projects, whether they are accomplished for another division in a company or for a regular paying customer. Application of the 100% Rule enables accurate costing, which is essential to budgeting similar efforts in the future.
References
- ↑ S1 Cleland, David I. and Roland Gareis, Global Project Management Handbook, McGraw Hill Professional, 2006
- ↑ Eric S. Norman, Shelly A. Brotherton, Robert T. Fried Work Breakdown Structures: The Foundation for Project Management Excellence, Wiley, 2010
- ↑ "Background and Key Concepts COPYRIGHTED MATERIAL." Web. 20 Sep. 2015
- ↑ Military-Standard-881C, 3 October 2011
- ↑ "Guide, A. "Project Management Body of Knowledge (PMBOK® GUIDE & STANDARD)." Project Management Institute. 2001.
- ↑ Haugan, Gregory T. 2002. Effective Work Breakdown Structures. Vienna, VA Management Concepts
