Practice Standard For Work Breakdown Structures Pdf Download
Dibe Naro
The work breakdown structure provides a common framework for the natural development of the overall planning and control of a contract and is the basis for dividing work into definable increments from which the statement of work can be developed and technical, schedule, cost, and labor hour reporting can be established.[6]
A work breakdown structure permits the summing of subordinate costs for tasks, materials, etc., into their successively higher level "parent" tasks, materials, etc. For each element of the work breakdown structure, a description of the task to be performed is generated.[7] This technique (sometimes called a system breakdown structure[8]) is used to define and organize the total scope of a project.
The concept of work breakdown structure was developed with the Program Evaluation and Review Technique (PERT) by the United States Department of Defense (DoD). PERT was introduced by the U.S. Navy in 1957 to support the development of its Polaris missile program.[13] While the term "work breakdown structure" was not used, this first implementation of PERT did organize the tasks into product-oriented categories.[14]
By June 1962, DoD, NASA, and the aerospace industry published a document for the PERT/COST system, which described the WBS approach.[15] This guide was endorsed by the Secretary of Defense for adoption by all services.[16] In 1968, the DoD issued "Work Breakdown Structures for Defense Materiel Items" (MIL-STD-881), a military standard requiring the use of work breakdown structures across the DoD.[17]
Mutually exclusive: In addition to the 100% rule, there must be no overlap in scope definition between different elements of a work breakdown structure. This ambiguity could result in duplicated work or miscommunications about responsibility and authority. Such overlap could also confuse project cost accounting.
If the work breakdown structure designer attempts to capture any action-oriented details in the WBS, the designer will likely include either too many actions or too few actions. Too many actions will exceed 100% of the parent's scope, and too few will fall short of 100% of the parent's scope. The best way to adhere to the 100% rule is to define WBS elements in terms of outcomes or results, not actions. This also ensures that the WBS is not overly prescriptive of methods, allowing for greater ingenuity and creative thinking on the part of the project participants. When a project provides professional services, a common technique is to capture all planned deliverables to create a deliverable-oriented WBS.[21] Work breakdown structures that subdivide work by project phases (e.g. preliminary design phase, critical design phase) must ensure that phases are clearly separated by a deliverable also used in defining entry and exit criteria (e.g., an approved preliminary or critical design review).
If the WBS element names are ambiguous, a WBS dictionary can help clarify the distinctions between WBS elements. The WBS Dictionary describes each component of the WBS with milestones, deliverables, activities, scope, and sometimes dates, resources, costs, quality.According to the Project Management Institute, the WBS dictionary is defined as a "document that provides detailed deliverable, activity, and scheduling information about each component in the work breakdown structure."[4]
It is common for work breakdown structure elements to be numbered sequentially to reveal the hierarchical structure. The purpose of the numbering is to provide a consistent approach to identifying and managing the WBS across like systems regardless of vendor or service.[22] For example, 1.1.2 Propulsion (in the example below) identifies this item as a Level 3 WBS element, since there are three numbers separated by two decimal points. A coding scheme also helps WBS elements to be recognized in any written context and allows for mapping to the WBS Dictionary.[23]
The lowest element in a tree structure, a terminal element, is one that is not further subdivided. In a Work Breakdown Structure such elements (activity or deliverable), also known as work packages, are the items that are estimated in terms of resource requirements, budget and duration; linked by dependencies; and schedule. At the juncture of the WBS element and organization unit, control accounts and work packages are established, and performance is planned, measured, recorded, and controlled.[25] A WBS can be expressed down to any level of interest. Three levels are the minimum recommended, with additional levels for and only for items of high cost or high risk,[26] and two levels of detail at cases such as systems engineering or program management,[27] with the standard showing examples of WBS with varying depth such as software development at points going to 5 levels[28] or fire-control system to 7 levels.[29]
The adjacent figure shows a work breakdown structure construction technique that demonstrates the 100% rule and the "progressive elaboration" technique. At WBS Level 1 it shows 100 units of work as the total scope of a project to design and build a custom bicycle. At WBS Level 2, the 100 units are divided into seven elements. The number of units allocated to each element of work can be based on effort or cost; it is not an estimate of task duration.
The first question that someone should ask is why use a Work Breakdown Structure (WBS) at all. The work breakdown structure approach allows us to visually see the work that is needed in order to complete a project. The bottom line is by using a work breakdown structure it reduces the number of surprises and improves the ability to better estimate future projects.
First, let's start with some basics: The PMBOK describes the work breakdown structure as "a deliverable-oriented hierarchical decomposition of the work to be executed by the team". This is a way of describing the work so that the team knows exactly what work is needed in order to meet the goals of the project. In many cases, a work breakdown structure is the first transition of organizational goals into real work that people can actually perform. It helps to provide clarity of the scope for the project and "breaks down" the scope into whole work units.
A work breakdown structure is deliverable-oriented. So what is a deliverable? In a word, it can best be described as a noun. What is the difference between "write xyz specifications" and "xyz specifications"? One describes the end product and the other describes a single step to produce it. The end product is described as a noun without a verb. A deliverable can be delegated to a team or leader who can then be responsible for the work product and complete work should be returned when complete. A work breakdown structure is complete when all of the deliverables necessary to obtain the project goals are identified.
A work breakdown structure is a hierarchy. That means that deliverables can be further decomposed into parent and child relationships. In this case "xyz specification" may be further decomposed into "xyz functional specifications" and "xyz performance specifications". It is important that if decomposing the deliverable that the lower child decomposition represents 100% of the parent. This is similar to how we learned to outline our writing in our freshman English class. We can continue decomposing the deliverables until we feel comfortable that we have defined in a way that we can effectively manage and control the project.
Simply put the work breakdown structure technique divides projects into smaller more manageable chunks that can be more easily estimated and controlled. It gives a black and white version of the work effort needed and almost as important if the work is not in the work breakdown structure it is not a part of the project. The work should be decomposed until it is clear to teams performing the work. This provides a clear line of sight between the work and the goals for the project.
A work breakdown structure is typically presented in the form of an organization chart-like structure. It can be presented as a list, idea map or outline form as well. The key is to put it in a form that can most easily be used by both the team members and organizational leaders with the tools that your company uses most easily.
Since a work breakdown structure is displayed visually and contains summary information, it is easy to share across a team and with managers in an organization. Even on larger projects, the WBS can fit on a page or two. This allows the teams to more easily inspect the results and make adjustments. This view of the information can be used as a template for future projects. If you apply the WBS methodology in the PMBOK , future projects can leverage the work. Using this technique will improve work definition and speed up the planning process.
When you manage similar projects, the work breakdown structure gets better with every project and can become the basis for improved delivery management. For unique projects, the work breakdown structure can aid the team in making sure that deliverables and work packages are complete before involving more people in the planning process. Since it allows work to be distributed, multiple teams can be involved in planning simultaneously and the planning team has greater control over the planning process.
A work breakdown structure (WBS) is a visual, hierarchical and deliverable-oriented deconstruction of a project. It is a helpful diagram for project managers because it allows them to break down their project scope and visualize all the tasks required to complete their projects.
All the steps of project work are outlined in the work breakdown structure chart, which makes it an essential project planning tool. The final project deliverable, as well as the tasks and work packages associated with it rest on top of the WBS diagram, and the WBS levels below subdivide the project scope to indicate the tasks, deliverables and work packages that are needed to complete the project from start to finish.
08ab062aa8