INTRODUCTION

To success the management of any type of project you need to  use the right  planning techniques  :

• First to define the project objectives in sufficient detail
• Second to support effective management of the project.

The Work Breakdown Structure (WBS) is the foundation of any  planning :

It's not only defines the Work relates to project objectives but also :

• Establishe the structure for managing the work to its completion.
• The project’s work in terms of deliverable and their decomposition into components.
• Define the project’s life-cycle process in terms of process deliverables appropriate to that project and organization.
• Eavaluate the Effort & Cost to be expended on :
  • supporting processes  (indirect producers)
  • ressources for the creation of the deliverables (dircet producers)
• The assigned responsibility for accomplishing and coordinating the work.
• The Project can be internally focused, externally focused, or both.

Deliverables for these projects can take the form of

• Products
• Services

Internally focused projets

Any common activity to produce deliverables as support processes to the project.

Externally focused projects

Produced outputs and deliverables to people or organizations outside the company to any type of customers, compnies or individuals.

Many projects produce both internally and externally focused deliverables.

A WBS should be routinely prepared in all cases.

Developing a WBS is an essential step during the initial phases of a project as soon as the basic scope has been identified.

The initial WBS may be created with limited scope information, however, it will require rework as additional scope information is developed or made available by more complete analysis of the project work to be performed.

This Article is a guide and provide a summary of insight into WBS development and application.

Following this guide will enable the user to prepare a useful and high-quality WBS.

OBJECTIVE

The primary objectives of this article are to provide a common ground for understanding the concepts and benefits of the WBS, and to present a standard application of the WBS as a project management tool.

Our intent is to encourage the consistent development of the WBS as a project management tool and, as a result, improvethe planning and control of projects.

What Is a Work Breakdown Structure?

COMMON USAGE OF TERMS

The following commonly used words have generally accepted meanings:

Work

Sustained physical or mental effort to overcome obstacles and achieve an objective or result including :

• activity
• duty
• function
• assignment
• effort
• exertion
• exercise of skill

Breakdown

• divide into parts or categories
• separate into simpler substance
• undergo decomposition.

Structure

The arranged in a definite pattern of organization.

These definitions imply that a Work Breakdown Structure (WBS) has the following characteristics:

• represent the work as an activity, and this work has a tangible result.
• arrange the work in a hierarchi structure.
• identfy the objective or tangible result, which is referred to as a deliverable
• provide  a deliverable-oriented grouping of project elements that organizes and defines the total work scope of the project.

Each descending level represents an increasingly detailed definition of the project work .

CONCEPT

Overview

The WBS elements assist the project stakeholders in developing a clear vision of an end product of the project and of the overall process by which it will be created.

The WBS divides the project scope into hierarchal, manageable, definable packages of work that balance the control needs of management with an appropriate and effective level of project data.

The various levels of the WBS aid in focusing communication with stakeholders and clearly identifying accountability to the level of detail required for managing and controlling the project.

The upper levels of the WBS typically reflect the major deliverable work areas of the project or phases in the project’s life cycle.

These levels also provide logical summary points for assessing performance accomplishments, as well as measuring cost and schedule performance.

The content of the upper levels varies depending upon the type of project and the industry in which it resides. Therefore, to avoid confusion and rework, it is often prudent to consider defining the labels for the different levels of the WBS prior to its construction. The lower WBS elements provide appropriate focus for scope, cost, and schedule development.

Whenever work is structured, easily identifiable, and clearly within the capabilities of individuals, project stakeholders can confidently expect the objectives associated with that work can and will be achieved.

Deliverables

A deliverable any measurable, tangible, verifiable outcome, result, or item that must be produced to complete a project or part of a project. Often used more narrowly in reference to an external deliverable, which is a deliverable that is subject to approval.

The WBS provides the foundation for subsequently integrating the work package details and deliverables with all other aspects of project initiating, planning, executing, controlling, and closing.

Work Package

A deliverable at the lowest level of the work breakdown structure, when that deliverable may be assigned to another project entity to plan and execute.

This may be accomplished through the use of a subproject where the work package may be further decomposed into activities.

Design

A well-developed WBS that presents information at the appropriate level of detail and in formats and structures meaningful to those performing the work is an invaluable tool in project management.

The WBS

Decomposes (or disassembles) the overall project scope into deliverables and supports the definition of the work effort required for effective management.

Clearly and comprehensively defines the scope of the project in terms of deliverables that the project participants and stakeholders can understand.

Supports documenting the accountability and responsibility for the various deliverables by having a direct relationship between the WBS elements related to the Organizational Breakdown Structure (OBS) identified through the Responsibility Assignment Matrix (RAM).

The WBS provides a structure for organizing the scope and subsequent information of the project’s progress, periodic status, and projected performance for which a project manager is responsible.

The WBS also supports tracking problems to their root causes to assist the project manager in identifying and implementing changes necessary to assure desired performance.

Management

The WBS supports effective project management in several ways during the life of a project by:

• Separating the deliverable into its component parts to ensure the project plan matches the approved project scope and will fulfill the overall objectives of the project.
• Supporting the decomposition into simpler components, providing one of the primary methods for managing complex projects.
• Supporting planning and the assignment of responsibilities.
• Assisting in determining resource requirements (i.e., skills, characteristics, and so on).
• Assisting in tracking the status of resource allocations, cost estimates, expenditures, and performance.

Organizational

The WBS provides the ability to relate the work defined to the responsible organizational units, subcontractors, or individuals.

As the work and organizational responsibilities become more clearly defined, individuals (including subcontractors) are assigned responsibility for accomplishing specific WBS elements within defined budgets and schedules.

Levels

The WBS includes all work to be done by the project stakeholders.

While in some application areas the WBS consists of a three-level hierarchy describing the entire effort to be accomplished by the primary organization, that number may not be appropriate for all situations. The depth of a WBS is dependent upon the size and complexity of the project and the level of detail needed to plan and manage it.

The WBS is intended to provide a clear statement of the objectives and deliverables of the work to be performed.

The WBS elements should represent identifiable work products (e.g., equipment, data, and services) encompassing the work to be performed by all parties.

In summary, the WBS:

• Defines the hierarchy of deliverables
• Supports the definition of all work required to achieve an end objective or deliverable(s)
• Provides a graphical picture or textual outline of the project scope
• Provides the framework for all deliverables across the project life cycle
• Provides a vehicle for integrating and assessing schedule and cost performance
• Provides the association to the responsible stakeholders
• Facilitates the reporting and analysis of project progress and status data
• Provides a framework for specifying performance objectives.

Project scope management

The processes required to ensure that the project includes all the work required, and only the work required, to complete the project successfully (Project Management Institute).

Based on this definition, the WBS has two goals:

• To ensure that the project includes all the work needed.
• To ensure that the project includes no unnecessary work.

Both of these goals are of great concern to the company management.

If the WBS does not meet either of these two goals, the project may fail.

If necessary work is omitted, the project will almost certainly be delayed and may experience cost overruns.

If unnecessary work is performed, the customer’s time and money will be wasted.

The WBS assists in developing a clear vision of the end product of the project and of the overall process by which it will be created, therefore, it aids in these areas.

Illustration of  how the entire project plan pivots on the WBS.

The WBS is the primary input to four core processes and one facilitating process:

• Activity Definition
• Resource Planning
• Cost Estimating
• Cost Budgeting
• Risk Management Planning.

As Figure above Guide illustrates, the entire project plan builds on these processes.

This makes the WBS the foundation for:

• ■ Coordinated and Integrated Planning : The WBS provides the basis for integrated project management across the Project Management Knowledge Areas and  Project Management Process Groups. It also provides the means for using project management software to its full capability.
• ■ Performance Reporting : The WBS organizes monitoring processes, as well as the cost and schedule performance metrics associated with the work.
• ■ Overall Change Control: The WBS provides for the identification of suitable management control points that are used to facilitate communication and control scope, quality, technical soundness, schedule, and cost performance.
• ■ Product Scope Management : The WBS development process facilitates conceptualization and definition of product details.

Successful project management depends on the project manager’s ability to effectively direct the project team to complete the project deliverables.

Through the WBS, the work to accomplish these deliverables is structured, assigned, scheduled, tracked, and reported. Work is then directly related to the schedule and the budget, supporting effective resource allocation and tracking.

COMMUNICATIONS

The WBS facilitates communication of information regarding project scope, dependencies, risk, progress, and performance between the project manager and Project Management and stakeholders throughout the life of the project.

Project stakeholders include allwho directly participate or have an interest in the outcome of the project, and include but are not limited to:

• Project Manager
• Project Team Members
• Customers
• Suppliers
• Management
• Regulators
• The Public/Community
• Sponsors
• Owners.

REPORTING

The WBS provides the project management team a framework on which to base project status and progress reporting.

The WBS can provide different perspectives of the project structure. For example, information can be reported by:

• Life-Cycle Phase
• Deliverable
• Work Package
• All of the above compared to past similarly structured projects
• All of the above relative to cost, schedule, risk, scope, and quality perspectives.

WBS related information (like budget and schedule) can be rolled up or collapsed, to a level of detail that can be understood by the appropriate project participants and stakeholders. In addition, it can be rolled up or collapsed, to a level of detail that can be understood by the appropriate audience, such as senior or middle managers.

How to Create a Work Breakdown Structure

OVERVIEW

The Work Breakdown Structure (WBS) can be created new, or it can reuse components from other WBSs.

When reusing existing components, WBS elements may be drawn from previous similar projects or from standard project templates that the organization has determined support accepted best practices.

The following sections in this chapter are presented as guides for use during the development of a WBS, and contain a number of topics for consideration:

• Guidelines for Preparation
• Basic Assumptions or Factors
• Measurement Considerations
• Includes Project Challenges for Consideration
• Aids in determining the Appropriate Level of Detail
• Discusses WBS Life-Cycle Considerations
• Addresses Risk Assessment
• Contains guidance for use when considering Resource Planning.

Some of the sections can be used as checklists for the development and refinement of the WBS.

PREPARING A WBS

The WBS envolves through an iterative consideration of the project’s purpose and objectives, functional/performance design criteria, project scope, technical performance requirements, and other technical attributes.

A high-level WBS can often be developed early in the conceptual stage of the project.

Once the project is defined and specifications are prepared, a more detailed WBS can be developed.

The WBS can assist the project manager and stakeholders in developing a clear vision of the end product(s) of the project and of the overall process by which it will be created.

The following should stimulate thought whendeveloping a WBS to manage the project:

• Think through the entire project. (Look at dividing high-level deliverables.)
• Think deliverables. (What is to be provided/what is required?)
• Think with the end in mind. (How will this component contribute to the finished deliverable?)
• Think through the production of the deliverables. (What methods? What special processes? What quality requirements? What inspections?)
• Have you formulated a vision of the final product in your mind?
• What are its constituent parts?
• How do the pieces work together?
• What needs to be done?

These thoughts and questions are intended to help the project manager develop a clear statement of what the product of the project and to help answer the question, “How does one eat an elephant?” Answer: “One bite at atime!”

The WBS is the technique for dividing “the elephant” (the project) into bite-sized pieces.
The following steps describe the general process for developing a WBS:

1. Step 1: Identify the final product(s) of the project and what must be delivered to achieve project success. A thorough review of high-level project scope documents (inputs such as statement of work [SOW], technical requirements documents, and so on) is recommended to ensure consistency between the WBS and the project requirements.
2. Step 2: Define the product’s major deliverables, which are often predecessor deliverables necessary for the project, but that in themselves do not satisfy a business need (e.g., a design specification).
3. Step 3: Decompose major deliverables to a level of detail appropriate for management and integrated control. These WBS elements normally tie to clear and discrete identification of stand-alone deliverable products.
4. Step 4: Review and refine the WBS until project stakeholders agree that project planning can be successfully completed and that execution and control will successfully produce the desired outcomes.

FACTORS TO BE CONSIDERED
 

In developing a WBS, the following basic assumptions should be considered:

• Each WBS element should represent a single tangible deliverable.
• Each WBS element should represent an aggregation of all subordinate WBS elements listed immediately below it.
• Each subordinate WBS element must belong to only one single parent (or superior) WBS element.
• The deliverables should be logically decomposed to the level that represents how they will be produced (designed, purchased, subcontracted, fabricated).

The partitioning of deliverables from higher levels within the WBS to lower levels must be logically related.

Deliverables must be unique and distinct from their peers, and should be decomposed to the level of detail needed to plan and manage the work to obtain or create them.

Deliverables should be clearly defined to eliminate duplication of effort within WBS elements, across organizations, or between individuals responsible for completing the work.

Deliverables should be limited in size and definition for effective control—but not so small as to make cost of control excessive and not so large as to make the item unmanageable or the risk unacceptable.

The WBS development process should provide a vehicle for flexibility, particularly when the scope of the project effort may change.

A well-managed project, however, will incorporate a rigorous change control process to document and manage scope changes. When work scope changes do take place, the WBS must be updated.

Each entry in the WBS representing subcontracted or externally committed deliverables should directly correspond to matching entries in the subcontractor’s WBS.

All deliverables are explicitly included in the WBS.

All significant reporting items (e.g., review meetings, monthly reports, test reports, and so on) are included and identified in the WBS.
 

All WBS elements should be compatible with organizational and accounting structures.

A coding scheme for WBS elements that clearly represents the hierarchical structure when viewed in text format should be used.

Technical input should be obtained from knowledgeable technical subject matter experts (SMEs), and communicated to and validated by other key SMEs assigned to the project.

WBS MEASUREMENT CONSIDERATIONS

It is strongly recommended that project management activities foster measurement of work accomplishment, as opposed to goal achievement by providing an integrated view across project components. Proper linking between the WBS and associated cost and schedule is critical if integrated analysis of cost, schedule, and performance is to be accomplished. In doing so, the project manager should keep the following in mind:

• Cost and schedule impacts can be determined only if there is a clear link between performance parameters and budgeted work packages via the WBS.
• This link is accomplished in order to obtain a “performance budget baseline” or the budget associated at the work package level.
• All work in the WBS must be estimated, resourced, scheduled, budgeted, and controlled. The WBS has two parts: the structure and the component defini-
• tion. It is the mechanism that divides and organizes the work scope into units of work so that each unit can be estimated, resourced, scheduled, budgeted,
• and controlled while progress is reported.
• Where there is a clear link between performance parameters and budgeted work packages via the WBS, the linkage should be made at a high level within
• the WBS. All work packages can then be associated with the performance parameters.

Separate WBS elements should be included for integration tasks where several components are being brought together to create a higher-level WBS element.

By identifying the integration work separately where ever the above occurs, performance measurement information will provide a timely indication that problems are emerging.

Cost and schedule variances occurring in WBS elements that contain integration work can also indicate potential future rework in areas that have previously been completed. When these trends are projected, the result could be a far greater impact on revised estimates at completion than from projections of trends in other areas. Technical experts canprovide guidance regarding potential integration problems, which can help the project manager decide whether or not to create these separate integration and assembly (I&A) WBS elements.

Identification and tracking of performance metrics in a disciplined and systematic fashion helps provide significant early warning of potential problems and their nature.

CHALLENGES TO BE CONSIDERED

Challenges associated with developing the WBS include:

• Balancing the project definition aspects of the WBS with the data collecting and reporting requirements. (Remember that the primary purpose of the WBS is to define the project’s scope through the decomposition of deliverables.)
• Each WBS is a tool designed to assist the project manager with decomposition of the project only to the levels necessary to meet the needs of the project, the nature of the work, and the confidence of the team. Excessive WBS levels may require unrealistic levels of maintenance and reporting.
• Developing a WBS that defines the logical relationships among all the components of the project. This is generally clarified through the use of a dependency network in the project schedule.
• Ensuring the development and utilization of the WBS. Omitting WBS development and proceeding directly to the network diagram (such as a Gantt chart, CPM Schedule, or Precedence Diagram) may lead to unforeseen and unexpected difficulty, including project delay.
• Avoiding the creation of WBS elements that are not deliverable-focused (for example, structuring the WBS strictly by process or organization).
• WBS elements that are not deliverable-focused may lead to project failure.
•  Defining WBS elements representing opening and closing stages such as planning, assembly, and testing.
• Identifying and detailing all key project deliverables (e.g., regulatory permits, packaging, distribution, or marketing).
• Preventing the use of WBS elements that define overlapping responsibilities for the creation of a deliverable(s). Each WBS element must have one person who is clearly accountable for its completion.
• Identifying key project management work such as:

  • process management

  •  services and provisioning

  •  information/communication

  •  administrative documentation, training, and software.

These should be defined as level-of-effort WBS elements in those cases where they may be interim deliverables, do not themselves generate discrete deliver ables, and may not be included in the final project deliverables.

WBS LEVEL OF DETAIL

Overview

The WBS development process has been described as proceeding to successive levels of increasing detail until a level is reached that provides the needed insight for effective project management. This process can be summarized in the check list, which provides guidance for determining the need for further decomposition of the work. If the answers to most of the items in the checklist are positive, then further decomposition should be considered.

Note: Not all legs of the WBS must be symmetrical in terms of the number of levels developed.

There is no need to decompose all legs of the WBS if the need is only present in one area.

Determining Appropriate WBS Level of Detail

Should the WBS be decomposed further? Questions for consideration:

• Is there a need to improve the accuracy of the cost and duration estimates of the WBS element?
• Is more than one individual or group responsible for the WBS element? While there may be a variety of resources assigned to a WBS element, there should
• be one individual assigned overall responsibility for the deliverable created during the completion of the WBS element.
• Does the WBS element content include more than one type of work process or more than one deliverable?
• Is there a need to precisely know the timing of work processes internal to the WBS element?
• Is there a need to separately define the cost of work processes or deliverables internal to the WBS element?
• Are there dependencies between deliverables within a WBS element to another WBS element?
• Are there significant time gaps in the execution of the work processes internal to the WBS element?
• Do resource requirements change over time within a WBS element?
• Do prerequisites differ among internal deliverables within the WBS element?
• Are clear, objective criteria missing for measuring progress for the WBS element?
• Are there acceptance criteria applicable before the completion of the entire WBS element?
• Are there specific risks that require focused attention to a portion of the WBS element?
• Can a portion of the work to be performed within the WBS element be scheduled as a unit?
• Is the WBS element clearly and completely understood to the satisfaction of the project manager, project team members, and other stakeholders,including thecustomer?
• Is there a stakeholder interested in analyzing status and performance of only a portion of the work covered by the WBS element?

As identified earlier, the level of the detail in a WBS is a function of the size of the project and a balance between complexity, risk, and the project manager’s need for control. The level of detail may also vary during the evolution of a project.

A top-down and bottom-up analysis of the WBS can clarify whether the WBS is both complete and defined at the proper level of detail.

Short-duration projects may lend themselves to decomposition to appropriate levels of detail at the outset, while projects of longer duration and higher complexity may preclude decomposition of all deliverables until further in the future.

Again, this may mean that on any given project, some portions of the WBS may have different levels of decomposition. This is especially true when doing rolling wave planning, where the plan is detailed for the immediately upcoming work only and work far in the future is defined at a high level until later in the project life cycle.

WBS LIFE-CYCLE CONSIDERATIONS

Decomposition of complex requirements into simpler components provides one of the primary methods for handling complex projects. WBS development is the technique for accomplishing this decomposition. In structuring the WBS, one must look to the future and determine how the work will be accomplished and managed.

The WBS should reflect this structure. In addition to strict end-product identification, the WBS may also reflect level-of-effort functions such as project management activities and life-cycle timing (project phases). These other elements should only be used, however, to the required level of detail necessary to organize the work tasks. Remember that each of the lowest-level WBS elements should reflect work with specific, tangible deliverables.

PROJECT RISK AND THE WBS

Overview

For projects with highly related risk factors, a more detailed WBS is strongly suggested.

The risk events that might have a detrimental impact on the project are evaluated to identify and characterize specific risks.

Project risk is related to the likelihood of events positively or adversely affecting project objectives, including key elements such as technical design, quality, cost, and schedule.

The WBS decomposition approach may assist in risk identification and mitigation. For instance, projects that require permits and approvals from regulatory authorities can be high risk.

Since risk can impact several WBS elements, it would be prudent for the project manager to perform impact analyses against all WBS elements, thus isolating the risks, providing for individual treatment, and permitting more effective focus for risk management.

The first step in this technique is to review the WBS elements to the level being considered and segment them into risk events.

This review should consider the critical areas (requirements analysis/development, design and engineering, technology, logistics, and so on) and other factors that may help to describe risk events.

Using information from a variety of sources such as program plans, prior risk assessments, and expert interviews, the risk events are examined within critical areas to determine the probability of occurrence, severity of consequence (impact), and interdependency.

The risks associated with an effort may also define the level of detail necessary. Additional detail in high-risk areas provides for better assumption definition, as well as improved cost estimates and time assessment. This forced structuring provides an opportunity to define the assumptions and expectations at a controllable level.

Risk planning can be incorporated directly into the WBS by defining and including contingency activities as successors to the risk-impacted activities.

The duration of the contingency activities are set to compensate for the degree of uncertainty and potential impact of the risk event. As an example, a permit contingency activity could be created as a successor to the permit-application activity.

The duration of the permit-application activity is set to the normal time period expected for a permit application, and the duration of the contingency activity is set to reflect the probability and impact of the risk of delay.

The Relationship between Project Risk and the WBS

The following questions should be addressed for each WBS element when considering project risk:

• Are the deliverables completely and clearly defined?
• Will the quality of the work be evaluated through efforts such as testing and inspection?
• What is the likelihood of change?
• Is the technology changing faster than the project can be accomplished?
• Have manpower, facilities capability, availability of internal resources, and potential suppliers been checked?
• Is extensive subcontracting expected?
• Is management committed to the project and will they provide the support needed?
• Are requirements defined and approved?
• Has a formal change process been defined and implemented?
• Have metrics been defined for how the deliverables will be measured?
• Have resource requirements been identified for development of the project deliverables?
• Have other risks been identified, including stakeholder buy-in, public relations, management approval, team understanding, and project opposition?
• Has a communication plan (internal and external) been defined and implemented?
• Are third-party dependencies understood and monitored for change?
• Have alternate suppliers of required products, supplies, or expertise been identified?

RESOURCE PLANNING, MANAGEMENT, AND THE WBS

Overview

The WBS is decomposed to the level necessary to plan and manage the work.

Normally this will be at least one level below the reporting requirements , one that allows for the effective planning, control, and performance measurement of discrete activities with uniquely identifiable resources.

Although full resource identification will come later in the planning process, it can be useful to understand in general how that will be done, and ensure that
the level of detail in the WBS will support those efforts.

Resource Planning and Management

In order to prepare for adequate resource planning against the WBS, consider the following when examining the WBS level of detail:

• Is all the work planned to a degree of detail necessary to make and keep commitments?
• Is there an ability to establish and manage individual work assignments with the reporting structure indicated by this WBS?
• Can work assignments be established from a progressive expansion of the WBS?
• How will work generally be assigned and controlled?
• Will it be possible to reconcile individual work assignments to the formal scheduling system?
• How will budgets be established?
• Will it be possible to relate the budget to the proposed work assignments?
• Is the level of detail in the WBS appropriate for effective planning and control?
• Is the work defined by the WBS grouped in a logical manner?
• Is more than one organization involved (indicating the need to validate the WBS with others before doing detailed resource planning)?
• How will the status of work in progress be determined?

ADDITIONAL CONSIDERATIONS

The interrelationships between the specification of requirements, the WBS, the statement of work, resource plans, and the master and detailed schedules provides specific information relative to the relationship among cost, schedule, and performance.

Once the WBS is developed, it is important that the project manager and other stakeholders involved in the management of the project know “how things are going” on a regular basis. In this regard:

• Think reporting and control mechanisms.
• How will WBS element completion be determined?

EXAMPLE OF WBS LEVEL CODING

1. WBS Levels and Activity Coding Structure

   1. Level 0

Milestone

Engineering

Procurement

Sub-contract

Manufacturing & Delivery (MFD)

Construction

Commissioning