WBS: What is WBS?

WBS is also called work breakdown system. It is a map of the project, which identifies the products and work elements involved in the project. WBS is the output of a project with different levels of details. It defines the relationship between the final deliverable and its sub-deliverables, and in turn defines their work packages.

WBS helps the project manager to confirm that all the work has been determined and established.

How to carry out WBS sub-goal → task → work → activity?

decomposition rule

Principles of WBS decomposition:

The principle of 100% from horizontal to edge means that WBS decomposition cannot contain any missing items, nor can it contain any products or activities that are not within the scope of the project.

Vertical means that WBS decomposition should be fine enough to meet the purpose of task allocation, detection and control.

WBS decomposition method:

Full communication from top to bottom and from bottom to top

One-on-one communication

group discussion

The standard of WBS decomposition:

The activity structure after decomposition is clear.

Logically form a big event

All key factors are integrated.

Contains temporary milestones and monitoring points.

All activities are clearly defined.

Learn to break down tasks. Only by breaking down the tasks carefully enough can you know what you are doing, work in an orderly way and arrange your own schedule as a whole.

Work breakdown structure

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Work breakdown structure (WBS): deliverable-oriented grouping of project elements, which summarizes and defines that each descending level of the whole project scope represents a more detailed definition of project work.

Work breakdown structure (WBS) is the most important content in project management practice and PMP examination. WBS is always at the center of the planning process, and it is also an important basis for making progress plans, resource requirements, cost budgets, risk management plans and procurement plans. WBS is also an important basis for controlling project changes. The project scope is defined by WBS, so WBS is also a comprehensive tool for the project.

WBS has four main purposes:

1.WBS is a planning and design tool to describe ideas. It helps project managers and project teams to determine and effectively manage project work.

2.WBS is a structural design tool, which clearly shows the relationship between various projects.

3.WBS is a planning tool, which is used to show the whole project and explain in detail all the work that must be done to complete the project.

4.WBS defines milestone events, which can report project completion to senior management and customers as a reporting tool for project status.

Information that WBS should contain:

Project product or service structure, project organization structure, and project stage division.

WBS is a set of project elements oriented to project deliverables. These elements define and organize the overall work scope of the project, and the work not included in WBS does not belong to the scope of the project. Each level of WBS decline represents a more detailed definition and description of the project work. In the process of defining the project scope, the reason why the project deliverables should be further decomposed into WBS is that a better work breakdown can:

A. prevent missing the deliverables of the project.

B help the project manager to pay attention to the project objectives and define responsibilities.

C. Establish visual project deliverables to estimate workload and allocate work.

Help improve the accuracy of time, cost and resource estimation.

E. Help the establishment of the project team and gain the commitment of the project personnel.

Define benchmarks for performance measurement and project control.

G. clarify the job responsibilities of assisting communication.

H. establish a framework for other project plans.

Help analyze the initial risk of the project.

The lowest project deliverable of WBS is called work package, which has the following characteristics:

Work packages can be assigned to another project manager for planning and execution.

B the work package can be further decomposed into WBS of subprojects through subprojects.

Work packages can be further broken down into activities when making the project schedule.

D a work package can only be undertaken by one department or contractor. When it is used for subcontracting outside the organization, it is called a commitment package.

E the definition of work package should consider the 80-hour rule or the two-week rule, that is, the completion time of any work package should not exceed 80 hours. At the end of every 80 hours or less, only the completion of the work package is reported. Through this method of regular inspection, the change of the project can be controlled.

1. Method of creating WBS

Creating WBS refers to breaking down a complex project into a series of clearly defined project tasks and serving as a guiding document for subsequent planning activities. There are several ways to create WBS:

A. user's guide. Some organizations, such as the U.S. Department of Defense (DOD), provide guidelines for creating project WBS, such as MIL-STD.

B. analogy method. Create the work breakdown structure of a new project by referring to the work breakdown structure of similar projects.

C. top-down approach. Starting from the objectives of the project, the project work is gradually decomposed until the participants are satisfied that the project work has been completely defined. This method can estimate the project duration, cost and resource requirements more accurately, because it can define the project work at an appropriate level of detail.

D. bottom-up approach. Starting with detailed tasks, the identified and recognized project tasks are classified to the upper level step by step until the project objectives are achieved. The main risk of this method is that all tasks may not be completely identified, or the identified tasks are too rough or trivial.

2. Basic requirements for creating WBS

When creating a WBS, you need to meet the following basic requirements:

A. The task should be in one place in WBS, and only in one place in WBS.

B. The content of the task in WBS is the sum of all WBS projects under it.

C. A WBS project can only be handled by one person. Even though there may be many people doing it, it can only be handled by one person, and others can only be participants.

D.WBS must be consistent with the implementation methods in actual work.

E. Project team members should actively participate in the creation of WBS to ensure the consistency of WBS.

F each WBS project must be recorded to ensure an accurate understanding of the scope of work included and excluded.

G.WBS must be able to adapt to inevitable changes, and at the same time, maintain the project work content normally according to the scope specification.

3.3 representation. Work breakdown structure (abbreviation of work breakdown structure)

WBS can be represented by a tree hierarchy diagram or a table with indentation.

In MIL-STD, the American defense agency described WBS as: "WBS is a product-oriented family tree composed of hardware, software, services, data and equipment."

In practical application, table WBS is widely used, especially in project management software.

4.WBS decomposition method

WBS can be decomposed in many ways, including:

A. decompose according to the physical structure of the product.

B. according to the function of the product or project.

C. decompose according to the implementation process.

D. according to the geographical distribution of the project.

E. decompose according to the objectives of the project.

F. broken down by department.

G. broken down by function.

5. The process of creating WBS

The process of creating WBS is very important because in the process of project decomposition, project managers, project members and all functional managers involved in the project must consider all aspects of the project. The process of establishing WBS is:

A. obtain ScopeStatement or StatementofWok (when contracting subprojects).

B convene relevant personnel to discuss all major project work collectively and determine the way of project work breakdown.

C. break down the project work. If you have a ready-made template, try to use it.

D. Draw the hierarchical structure diagram of WBS. Some work at the higher level of WBS can be defined as subprojects or sub-life cycle stages.

E. Subdivide the major project deliverables into smaller, manageable components or work packages. The work package must be detailed enough to estimate the work package (cost and duration), arrange the progress, make the budget, and assign the responsible personnel or organizational units.

F. verify the correctness of the above decomposition. If it is found that lower-level projects are unnecessary, modify the composition.

G. if necessary, establish a numbering system.

H. With the progress of other planned activities, continuously update or revise WBS until all work is covered.

Check whether WBS is defined completely and all tasks of the project are decomposed completely. You can refer to the following standards:

First, the status and completion of each task can be quantified.

J clearly defines the beginning and end of each task.

K. Every task has a deliverable.

The length of the construction period is easy to estimate and within an acceptable period.

Meter (short for meter) is easy to estimate the cost.

Each task is independent.

Use of 5.5. Work breakdown structure (abbreviation of work breakdown structure)

For WBS, a WBSDictionary needs to be established to describe each work part. WBS dictionary usually includes information such as work package description, progress date, cost budget and staffing. For each work package, it should contain as much information about the work package as possible.

When WBS and OBS are used together, an account code should be established. Account code is a coding system, which is used to uniquely identify each unit of the work breakdown structure of a project. Costs and resources are allocated to this coding structure.

6.6 Practical experience. Work breakdown structure (abbreviation of work breakdown structure)

Use up to 20 levels, and more than 20 levels is excessive. For some smaller projects, generally 4-6 is enough.

There is no need for all branches in WBS to decompose to the same level, that is, there is no need to force structural symmetry. In any branch, when it reaches a level, the required accuracy can be estimated and it can be stopped.