Integrated Master Schedule (IMS)/Integrated Master Plan (IMP) Application

Definition: The IMP comprises a hierarchy of program events, in which each event is supported by specific accomplishments, and each accomplishment is based on satisfying specific criteria to be considered complete. The IMS is an integrated, networked schedule of all the detailed, discrete work packages and planning packages (or lower level tasks of activities) necessary to support the IMP's events, accomplishments, and criteria.

Keywords: earned value management, EVMS, integrated master plan, integrated master schedule, program plan, work breakdown structure, WBS

MITRE SE Roles and Expectations: The IMS and IMP form a critical part of effectively providing acquisition support. MITRE systems engineers (SEs) should understand the use and implementation of these tools and how they can be used to effectively monitor program execution.

What We Know About the IMS and IMP

An Integrated Master Plan (IMP) and an Integrated Master Schedule (IMS) are not equivalent. An IMP is an event-driven plan that documents the significant accomplishments necessary to complete the work and ties each accomplishment to a key program event. It defines how the project will be organized, structured, and conducted and how the total process will be controlled to provide a product that satisfies stakeholder requirements. An IMS is an integrated and networked multilayered schedule of program tasks required to complete the work effort captured in a related IMP. It is linked to both the IMP and the work breakdown structure (WBS) and is an essential companion to the IMP.

The term "integrated master plan" is a DoD term and has no standard definition in the civil agency environment. If used in a civil agency environment, the term "IMP" must be a mutually agreed definition. In the DoD environment, the IMP normally is a bilateral agreement between the government and a contractor on what defines the "event-driven" program.

The IMS constitutes a program schedule of the entire required scope of effort, including the effort necessary from all government, contractor, and other key parties for a program’s successful execution from start to finish (the period of performance). The IMS is developed from the IMP, major contractor events, accomplishments, entrance criteria, exit criteria, and the WBS, which defines the program work structure and work packages. Like the IMP, the IMS is maintained, under configuration control, through disposal or program termination. An IMS may be made up of several individual schedules that represent portions of effort within a program. Different organizations may use the term "integrated master schedule" differently; for example, an IMS is often used to refer solely to the prime contractor schedule. In actual practice, the government IMS usually incorporates the summary level elements of the contractor's IMS, whereas the contractor's IMS, as its lowest tier, includes the individual activities necessary to complete each work package. The use of "integrated" here implies the schedule’s incorporation of all activities—those of the contractor and their subcontractor’s major event—necessary to complete a program.

Together, the IMP and IMS should clearly demonstrate that the program is adequately structured, realistic, and executable and that the planned tasks are achievable within schedule and cost constraints with an acceptable level of risk. During the proposal evaluation and source selection phases, the IMP and IMS are critical components of the offeror's proposal; they identify the offeror's ability to partition a program into tasks and phases that can be successfully executed to deliver the proposed capability. After contract award, the contractor and/or the government use the IMP and IMS as the day-to-day tools for executing the program and tracking program milestone status.

The IMP and IMS are business tools to manage and provide oversight of acquisition, modification, and sustainment programs. They provide a systematic approach to program planning, scheduling, and execution. They are equally applicable to competitive and sole source procurements with industry, as well as to government-only, in-house efforts. They help develop and support program/project budgeting and can be used to perform "what-if" exercises and to identify and assess candidate problem workarounds. Finally, use of the IMP/IMS focuses and strengthens the interaction between the government and contractor teams with respect to program execution.

Best Practices and Lessons Learned

Understand how the IMP and IMS differ. In general, think of the IMP as a planning tool and the IMS as the execution tool following the WBS from individual activities through work tasks to the final product. Note that the IMS is a scheduling tool for management control of program progression, not primarily for cost collection purposes.

  • The IMP is an event-driven plan in which the events are not tied to calendar dates; they are tied to the accomplishment of a task or work package as evidenced by the satisfaction of the specified criteria for that accomplishment. Accomplishments in the IMP should have criteria for determining completion with clear evidence so that the entire program team can understand the progress. The IMS is time driven, tied to calendar dates, and should be defined to the level of detail necessary for program execution.
  • The IMS is a hierarchical, tiered structure capable of rolling up to high-level summary representations of activities as well as breaking down to the lowest level of task details showing dependencies, resources, durations, and constraints.

Consider interrelationships. To build a reasonable IMP and IMS, you need to estimate the attributes of work products and work packages, determine the resources needed, estimate schedule durations, and identify and analyze program risks. The IMS should be traceable to the IMP events and accomplishments, be traceable to the WBS, be linked to the statement of work, and support the earned value management system (EVMS). The WBS specifies the work structure that the IMS should be built on and the EVMS should report on. A good WBS includes key work efforts partitioned into discrete elements that result in a product (i.e., document, software item, test completion, integrated product) or in measurable progress (percent complete is not recommended when the end state is not completely quantifiable—a software development issue, test procedures, or training materials). The IMP is placed on contract and becomes the baseline execution plan for the program/project. The IMS should not be placed on contract; it is often a contract deliverable.

Evaluate a contractor's IMS carefully. For evaluating a contractor's proposed IMS, the evaluator must be knowledgeable in and familiar with the contractor's technical proposal in the area of evaluation. The evaluator should focus on realistic task durations, predecessor/successor relationships, and identification of critical path tasks, viable resource loading at the task level and viable risk mitigation and contingency plans. A contractor's IMS should also include, at the appropriate fidelity level, key external dependencies, subcontractor tasks and deliverables, and government GFE/GFP/GFI deliverables. An IMS without lower tier detailed information may often result in obscuring critical execution elements and contributing to failure of the EVMS to accurately report progress (for more details on EVMS, see the SEG article Acquisition Management Metrics). An unsupported high-level IMS may also fail to show related risk management approaches being used, which often results in long duration tasks and artificial linkages masking the true critical path.

Establish measurable criteria. Criteria established for IMP accomplishments should be measurable (i.e., satisfactory completion of a test event, approval of a study report, or verification of an activity or test). Consider including critical performance requirements (key performance parameters or technical performance metrics) as accomplishment entrance or exit criteria.

Include relationships for multiple delivery/increment programs. On programs with multiple deliveries and/or multiple increments, ensure that the IMS includes cross-delivery order and cross-increment relationships. This is valuable when conducting critical path analyses on the IMS. These relationships sometimes drive "ripple effects" across the delivery orders and work packages. Insight into these relationships can be an extremely valuable factor when analyzing a critical path or estimating a "what if" or total cost for a modification.

Involve stakeholders. Relevant stakeholders (including user organizations, financial managers, and sustainment organizations) should be involved in the planning process from all life-cycle phases to ensure that all technical and support activities are adequately addressed in program plans such as the IMP and IMS.

Communicate via IMS. The IMS can be used to communicate with stakeholders on a regular basis. For enterprise systems with large numbers of external interfaces and programs, the IMS can be used as the integration tool to indicate and track milestones relevant to the other programs.

References and Resources

DAU, Defense Acquisition Guidebook, Chapter, Integrated Master Schedule (IMS), accessed June 7, 2016.

Department of Defense, October 21, 2005, Integrated Master Plan and Integrated Master Schedule: Preparation and Use Guide, Ver. 0.9, accessed September 14, 2017.

INCOSE, 2015, Systems Engineering Handbook, A guide for system life-cycle processes and activities, Fourth Ed., INCOSE‐TP‐2003‐002‐04.

Project Management Institute (PMI), 2013, Standard for Program Management, Third Ed


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