Work Breakdown Structure (WBS)

Work Breakdown Structure (WBS) is the outline and hierarchical divisions of the project scope of work that is defined, planned, managed, and controlled through subdividing the project scope of work into manageable segments by the structured organisation resources. A WBS is a task oriented and detailed breakdown by the code structure for tasks: a key project deliverable (teamwork with the elements of scope); responsibility; schedule and cost covering the entire project scope of work into manageable sections. (e.g., units, systems, disciplines, deliverables, etc.)

The Work Breakdown Structure (WBS) initiates the work activities (deliverables) responsibility matrix, the Organisational Breakdown Structure (OBS) initiates a team organisation (resources) base responsibility matrix, and a resource-based Cost Breakdown Structure (CBS) is the costs allocated to the lowest level of the WBS.

Cost Breakdown Structure (CBS) is the cost allocation to the lowest level of the Work Breakdown Structure (WBS). A CBS is a breakdown of the costs of the various components of the structure including all works or services done by the contractors or subcontractors. A CBS is used to continuously compare the actual cost with the budget, and integrated to the cost control system.

Organisation Breakdown Structure (OBS) is the hierarchical arrangement of the organisation of necessary resources to perform a job or project. An OBS is a breakdown of all human and material resources to identify and organise the resources and organisational responsibilities with carrying out activities associated with the project.

Project Control Structure is a project management tool to support the prioritised decisions based on analysis of variables such as schedule, deliverables, and resources, etc. The Project Control Structure is a breakdown of the total project scope of work into manageable systems, packages, units, and plant, identifying each item with the required resources. 

Work Package (WP) is a group of related items which is a logical subdivision of control accounts that is a measurable and controllable unit of the system within the total scope of work. A WP can be a simple task, activity, group of works, or total project work that is developed based on the Work Breakdown Structure (WBS). A WP is defined as the lowest level that is to plan, measure progress, calculate earned values, and distinguish from others, single responsible organisation, assigns budget and limited duration, target to start and finish date.

Construction Work Package (CWP) is defined a logical and manageable division of construction scope work that is enable the control of work execution based on geographical sequencing in order to maximise construction efficiency. A CWP is agreed on the same geographic areas with all Engineering disciplines that includes a brief statements of activity description, resources of skill and expertise, estimates of duration, risks, and budget, etc.

Responsibility Assignment Matrix (RAM) is the participation by various roles in an organisation to complete tasks used in clarifying roles and responsibilities for a project or business: Who will do What? A RAM is a chart showing the relationship between the contract Work Breakdown Structure (WBS) elements and the organisations assigned responsibility (OBS) for ensuring their accomplishment. (Also, called as the RACI (Responsible, Accountable, Consulted, and Informed))

Role and Responsibility (R&R) is a matrix chart identifying functional areas and relationships between the contract Work Breakdown Structure (WBS) elements and the role functions or assigned responsible members in the organisation that ensures the accomplishment in order to deliver a successful good, service or project.