How to create a Work Breakdown Structure?
Questions, this post answers:
- What is Work Breakdown Structure (WBS)?
- Why to create a WBS?
- How to create WBS?
- What is Work Package?
- What are Control Accounts?
- What is Planning Package?
- What is WBS Dictionary?
- What is decomposition?
- How to effectively decompose project work into balanced WBS?
Work Breakdown Structure?
Work Breakdown Structure (WBS) is a systematic hierarchical decomposition of project deliverables and work into smaller pieces so that project can be easily estimated, planned, resourced, tracked and reported. WBS is the foundation of all the planning and therefore it must be created carefully. Project planning will be as detailed as WBS. If WBS is not detailed enough, the planning remains at high level and will not solve the purpose.
Each descending level in the hierarchy represents an increasingly detailed definition. Lowest level component is called Work Package. Component at above Work Package are called Planning Package.
Forms of WBS
WBS may be created in various forms depending upon project type and execution methods. Following are some of the forms…
- Project phases at top level, deliverable at next level and sub-deliverables are at levels further down.
- Major deliverables at top level and sub-deliverables at second level. If sub-deliverables need to be further decomposed then further levels are created.
- If project is big, it is divided into sub-projects. Sub-projects come at top level. Each sub-project can be decomposed further using any of the form described in point 1 and 2.
- If various components are to be developed by organizations outside the project team (such as contract work), then team develops a WBS up to a work package to be assigned to outside organization. Further detailing is done by the organization to whom work package is assigned.
Figure 1( a, b, c) shows different forms of Work Breakdown Structure (WBS) and figure 2 shows an example of a WBS with project phases at top.
Figure 1a – WBS with project phases at top level
Figure 1b – WBS with project deliverabls at top level
Figure 1c – WBS with subproject at top level
Figure 2 – WBS Example – Solar PV Plant
How to create a WBS
- WBS is created using a technique call decomposition. Decomposition is a technique used for dividing and subdividing the project scope and project deliverables into smaller, more manageable parts.
- WBS is created by decomposing bigger deliverables into smaller deliverables and assigning identification code called WBS codes to each work package and planning package.
- Different branches of WBS can have different level of decomposition.
- Ability of plan, manage and control the work is enhance as work decomposed to greater level
- Excessive decomposition can lead to non-productive management efforts
- It is important to ascertain that degree of decomposition is necessary and sufficient
- After decomposition nothings should be left out and no extra work is included (Rule 100%)
- Decomposition is considered reached to an appropriate level when work package can be easily estimated, can be allocated to a team member or a group and can be tracked easily.
Output of WBS creation process
WBS creation process produce following…
- WBS
- Complete Work Breakdown Structure which is necessary and sufficient and contains complete scope of the project that is to be delivered.
- Work package
- Lowest level components in WBS hierarchy
- Planning package
- Intermediate level components in WBS hierarchy
- A WBS component below the control account and above the work package that contains known work but without detailed schedule activities
- WBS dictionary
- A document that provides detailed deliverable, activity, and scheduling information about each component in the work breakdown structure.
- May include Description of work, assumptions, constraints, responsible organization/person, milestones, resources required, Cost estimates, acceptance criteria etc.
- Control Accounts
- A control account is a management control point where scope, budget, and schedule are integrated and compared to the earned value for performance measurement.
- A control account may include one or more planning and work packages. One work package must be associated to one control account.
- Each control account is assigned a unique code or account number(s) that links directly to the performing organization’s accounting system.
- In practice cost centre is a good examples of control account.
WBS is the foundation of planning and should be carefully prepared. Your planning will be as detailed your WBS. A well thought WBS lead to a meticulous planning which is a road map for project success. It has specific application for Microsoft Project Scheduling. A good WBS help you to put up a detailed schedule in MS Project. It helps providing right estimates, establishing dependencies properly and appropriate allocation of resources.