Best practices for creating a Work Breakdown Structure

In an earlier article, I described why a WBS is so important. But in order to be a usefull tool, you shall respect some best practices. I will discribe bellow some of those.

1. Use a top-dow approach. Begin at the project goal level and break the work successively to lower levels of definition.
   
2. Create it with the input from domain experts and team members.
   
3. Do not include any work which is not part of the project.
   
4. Cover the entire scope of the project at least at the upper level of the WBS (In a iterative development aproach, the WBS is developed iteratively, thus the entire scope will be only at the end of the project available). But in early phases, the entire scope of the project can be covered in the in the high level WBS components.
   
5. Each component of the WBS, excepting the highest one, is a part of the parent WBS component.
   
6. The lowest level of the WBS shall have the following properties:
   

• It is possible to estimate its need for ressources, duration and costs. Aggregating this information for each lowest level work package you can calculate the ressources, duration and costs for the entire project.
  
• The start and the end of the execution can be clearly defined.
  
• It's realization can be outsourced. That is true mainly for work packages to an upper level in a WBS. The outsourcer can further decompose that work package.
  
• It has a deliverable or a clear part of it. The deliverable is a prove that the work package is complete.
  
• It can be completed within reasonable time limits. There is no universally accepted rule regarding the length of an work package. However, it  shall not exceed 1-2 weeks to complete.
• Specific to the software development projects, it can be executed by a single developer.

The Work Breakdown Structure (WBS): Why a WBS is so important?

The Work Breakdown Structure (WBS) is, no doubts, the most valuable project management tool. According with the definition from PMBoK (Project Management Body of Knowledge), the WBS is a deliverable oriented hierarhical decomposition of the work to be executed by the project team to achieve the project objectives and to create the requested deliverables.

It is a good practice to use a WBS for any project, even if a project is a small one. But why a WBS is so important? What are the benefits of using a WBS for your project?

First of all, through logical decomposition, a project manager or the project team is able to determine all the work which is needed to fulfill the project objectives and to deliver the project deliverables. Through successive decomposition the work is decomposed in smaller, more manageable, work packages. Those resulting work packages can be further used for ressource estimation, scheduling and cost estimation. It is so because it is much easier to estimate the smaller pieces of work. In addition for having a solid ground for your planning, by having a good foundation for your estimations, you can confidently go to your managers to request more ressources, more time and bigger budget.
Furthermore, it helps to understand much better the project. By assesing each work package, and the relationships between them, you can understand the risks for your project. In addition since the WBS covers the entire scope of the project, you can asses correctly the impact of the scope changes.
Not to neglegt are the advantages which a WBS brings to the communication. Stakeholders can easier understand your project having in front a WBS showing the work packages which have to be executed. Furthermore, team members can understand the big picture and their role in the project.
But how can you create a good WBS? What are the best practices for creating it? We will have a look about in the next episode regarding WBS.