2.2.3 Determining Levels of Program WBS. The detailed
technical objectives are defined and specified work tasks are assigned to each
WBS element. Resources, materials, and processes required for attaining
the objectives are added incrementally. The linkage between the requirements
specification, the WBS, the Statement of Work (SOW), the Integrated Master
Schedule (IMS), and Integrated Master Plan (IMP) provides specific insights
into the relationship between cost, schedule, and performance. This
relationship allows all items to be tracked to the same WBS elements.
Therefore, the levels of the Program WBS should be related to these
requirements and conform to the product-oriented family tree.
Following the Acquisition Management Framework (see Figure 1-1), when developing a Program
WBS, systems engineers define the description of the system and its related
levels. Early in the Concept Refinement phase an Initial Capability
Document (ICD) through the Joint Capability Integration and Development System
(JCIDS) is developed and systems engineering efforts transform operational
needs to system performance parameters and configurations. For example,
suppose the established need is to “Kill a Tank.” The objective is clear and
can be met through numerous capabilities. Systems engineers perform tradeoffs,
which ultimately define the preliminary system level functions. In this case,
the systems that will “Kill Tank” must be able to detect, maneuver, and shoot
(see Figure 2-1). The Program WBS is not formed around these functional
requirements, but is developed out of the products which are expected to
satisfy these requirements. Therefore, during the Concept Refinement
phase, no formal WBS is defined.
FIGURE 2-1: Functional Requirements in the
Concept Refinement Phase
When the Technology Development phase is
initiated, a Capability Development Document through the JCIDS is
developed. Through this development process, the systems engineering
efforts will focus on technology needs to meet system level capabilities.
Functional requirements are assigned under a System, all meeting the mission
need of “Kill Tank.” If Government laboratories or in-house engineering
support is accomplishing this work, a SOW may be prepared for a request for
support in the Technology Development phase. Otherwise, this may have
already been accomplished at the end of Concept Refinement to obtain
contractual support for the Technology Demonstration phase.
The Technology Development phase should
describe the system and the configuration items that make up the system.
Once the system concept is determined, then major subsystems and configuration
items can be identified and lower level functions defined, so that lower level
system elements can be created. Again, these are not WBS elements since they
do not reflect a product. In this example, using a cost effectiveness tradeoff
process determined that a fire control system of an aircraft can meet the
mission need. The fire control system is functionally able to detect, aim,
track, and fire (see Figure 2-2).
FIGURE 2-2: Idenification of Major Subsystems
and Functional Requirements
The relationship of the functions shown
in the previous example can now be translated into products that will meet the
mission need requirement. It is at this time that the preliminary Program WBS
can be defined.
Generically, the WBS is defining the
solution to the problem in terms of a product. (see Figure 2-3) This figure
shows the hierarchical relationship of the Aircraft System to the Fire Control
Subsystem and to other elements.
FIGURE 2-3: Program WBS
When System Development and Demonstration
(SDD) units are being developed and produced, the Program WBS should be
approved by submitting a Cost and Software Data Report (CSDR) plan, as
required by DoD Instruction 5000.2. The plan describes the Program WBS being
used and defines the approach the Government activity plans to use for
collecting cost data.
During the SDD phase, through the JCIDS
process, systems engineering efforts develop a Capabilities Production
Document (CPD) and define the system configuration to its lowest level. By the
end of this phase, the total system definition is complete and the Government
has approved the Program WBS and each Contract WBS. As the system becomes
better defined, the contractor extends the Contract WBS to the desired level,
reflecting how each program is planned and will be managed. The WBS levels
should be directly linked with the detailed system configuration.
Once the system has been defined, the
relationship between the Program WBS and the Contract WBS can be shown. Figure
2-4 shows how the Prime Mission System is the Government Program WBS. As a
result, multiple contract WBSs may be formed. In this example an Air Crew
Training Device and Fire Control Subsystem are assumed to be separate
contracts therefore each has a Contract WBS associated with it.
FIGURE 2-4: Work Breakdown Structure Matrix
(Click on image to enlarge)
During the Production and Deployment
phase, the system is produced as defined throughout previous phases. The
systems engineering efforts are actively involved in maintaining control over
the system configuration as it is produced. The WBS is defined to the
level appropriate for contract management and maintenance. When major
modifications occur, the same WBS can be tailored; or, if the changes are
substantial, a new WBS can be developed according to the same rules.
188.8.131.52 Creating the WBS
Dictionary. As part of developing a Program WBS, the program
manager will also develop a WBS dictionary. The dictionary lists and defines
the WBS elements. Although initially prepared by the Government program
manager, the contractor expands the dictionary as the Contract WBS is
developed. The initial WBS dictionary should be based on the generic
definitions in this handbook, made program specific to define the products
The dictionary shows the hierarchical
relationship of the elements and describes each WBS element and the
resources and processes required to produce it (see Figure 2-5). It also
provides a link to the detailed technical definition documents. The WBS
dictionary should be routinely revised to incorporate changes and should
reflect the current status of the program throughout the program’s