Major Capability Acquisition (MCA)

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Operations and Support (O&S) Phase

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Reference Source: DODI 5000.85 Section 3.15


This phase executes the PSS, satisfies materiel readiness and operational support performance requirements including personnel training, and sustains the system over its life cycle, including disposal. The O&S phase begins upon fielding of the first system(s), which may precede IOC, and is based on an MDA-approved PSS. This phase includes two major efforts: sustainment and disposal. The MDA-approved PSS is the basis for the activities conducted during this phase.



During this phase the PM will deploy the support package and monitor its performance according to the PSS. The PM will ensure that resources are  programmed; IP deliverables and associated license rights, tools, equipment, and facilities have been programmed and acquired to support each of the levels of maintenance that will provide PS; and necessary organic depot maintenance capability, consistent with statute and the PSS, are established. A successful program meets sustainment performance requirements without compromise to the security and integrity of the capability or service delivery, remains affordable, and continues to seek cost reductions by applying “should cost” management and other cost reduction techniques.


During O&S, the PM will measure, assess, and report system readiness using sustainment metrics, and implement corrective actions for trends diverging from the required performance outcomes defined in the APB and the PSS. Over the program life cycle, operational needs, training requirements, technology advances, evolving threats, process improvements, fiscal constraints, plans for follow-on systems, changes to the industrial base, or a combination of these influences may warrant revision to the PSS.


When revising the PSS, the PM will revalidate the supportability analysis and review the most current PS requirements, senior leader guidance, and fiscal assumptions to evaluate system support changes or alternatives to determine best value.



At the end of its useful life, a system will be demilitarized and disposed of in accordance with all legal and regulatory requirements and policy relating to safety (including explosives safety), security, and the environment, in accordance with the PSS. Disposal planning will include consideration of retirement, disposition, and reclamation.

Risk Management in O&S Phase

Reference Source: DoD Risk, Issue, and Opportunity Management Guide for Defense Acquisition Programs, Jan 2017

In the Operations and Support (O&S) phase, the risk activities include monitoring in-service usage, problem reports, parts availability/obsolescence, engineering modifications, technology insertions, and operational hazard risks. The Service support organizations often work with the program offices.

During this phase, programs should plan for and establish In-Service Reviews (ISR). The ISR is a multi-disciplined assessment to characterize the in-service health of the deployed system and the enabling system elements (training, user manuals, documentation, etc.). Risk management activities in the course of the ISR include risk assessment of operational hazards, product baseline integrity, supply chain status, determination of acceptable operational hazard risk, and in-service usage/support risk.

Systems Engineering in O&S Phase

Reference Source: DAG CH 3-3.2.6 Operations and Support Phase

The objective of the Operations and Support (O&S) phase is to execute a support program that meets operational support performance requirements and sustains the system in the most cost-effective manner over its total life cycle. Planning for this phase begins in the Materiel Solution Analysis (MSA) phase, matures through the Technology Maturation and Risk Reduction (TMRR) and Engineering and Manufacturing Development (EMD) phases, and is documented in the Life-Cycle Sustainment Plan (LCSP). Systems engineering (SE) in the O&S phase assesses whether the deployed system and enabling system elements continue to provide the needed capability in a safe, sustainable and cost-effective manner. SE efforts consist of data collection, assessment and corrective action cycles to maintain a system’s operational suitability and operational effectiveness.

Sustainment activities supporting system operations begin in this phase and should address two major efforts: life-cycle sustainment and disposal. SE efforts during life-cycle sustainment include Environment, Safety and Occupational Health (ESOH) assessments, technology refresh, functionality modification and life-extension modifications. (See CH 3–4.3. Design Considerations for other technical factors needing continued attention during this phase.)

When the system no longer provides an effective or efficient capability to the warfighter, the Department should make an informed decision to either modify or dispose of it. However, a related proactive aspect in the Production and Deployment and O&S phases is engineering analysis to identify potential obsolescence impacts (i.e., Diminishing Manufacturing Sources and Material Shortages (DMSMS)). DMSMS problems are an increasing concern as the service lives of DoD weapon systems are extended and the product life cycle for high-technology system elements decreases (see CH 3–4.3.8. Diminishing Manufacturing Sources and Material Shortages).

SE Roles and Responsibilities in O&S Phase

Reference Source: DAG CH 3-3.2.6 Operations and Support Phase

In addition to the general responsibilities identified in CH 3–2.5. Engineering Resources, the Program Manager (PM) focuses on the following O&S activities, which rely on and support SE efforts include:

  • Working with the user to document performance and sustainment requirements in performance agreements, specifying objective outcomes, measures, resource commitments and stakeholder responsibilities.
  • Employing effective Performance-Based Life-Cycle Product Support implementation and management.
  • Maintaining operational readiness.
  • Following acquisition program practices for major modifications or Service Life Extension Program (SLEP).
  • Supporting the Configuration Steering Board

In addition to the general responsibilities identified in CH 3–2.5. Engineering Resources, the Systems Engineer is responsible for the following tasks:

  • Refining the maintenance program to minimize total life-cycle cost while achieving readiness and sustainability objectives.
  • Assessing end-user feedback and conducting engineering investigations as required.
  • Leading teams to translate end-user feedback into corrective action plans and recommending technical changes.
  • Developing and implementing approved system proposed changes to ensure end-user needs continue to be met.
  • Conducting ESOH risk assessments and maintaining oversight of critical safety item supply chain management.
  • Conducting analysis to identify and mitigate potential obsolescence impacts (i.e., Diminishing Manufacturing Sources and Material Shortages (DMSMS)).
  • Supporting implementation of follow-on development efforts in response to formal decisions to extend the weapon system’s service life (e.g., through a Service Life Extension Program (SLEP)) or to initiate a major modification (may be treated as a stand-alone acquisition program).
  • Updating and maintaining system certifications and external SoS interfaces.
  • Supporting the PM in his interactions with the Configuration Steering Board.

SE Inputs for O&S Phase

Reference Source: DAG CH 3-3.2.6 Operations and Support Phase

  • Acquisition Decision Memoranda (ADMs) associated with Milestone C and Full Deployment (FD) decision review (DR)
    • ADMs may contain additional direction
    • O&S may start as early as Milestone C (e.g., software) and overlap P&D phase
    • FD DR would involve O&S
  • Trade-off analysis results
    • P&D phase trade studies may support manufacturing or other system modifications (technology insertion, technology refresh, etc.)
  • ESOH analyses (updated)
    • ESOH analyses continue during O&S to include hazard analysis and supporting NEPA/EO 12114 compliance for modifications and disposal Risk assessment (See CH 3–4.1.5.)
  • Interdependencies/interfaces/memoranda of agreement (MOAs)
  • System performance specification
  • Field failures
  • Other technical information, such as architectures, system models and simulations generated during the P&D phase LCSP (See CH 4–3.4.)
  • Information Support Plan (ISP) of Record (See CH 6–3.8.)
  • Test and Evaluation Master Plan (TEMP) (See CH 8–4.4.)
  • Request for Proposal (RFP) for SE support to O&S activities
  • Program Protection Plan (PPP)
  • Other analyses
    • End-user feedback and trouble reports
    • Other prior analytic, prototyping, and/or technology demonstration efforts conducted by the science and technology (S&T) community
  • Inputs for O&S Phase
    • Technology insertion/transition studies can occur at any point in the life cycle
  • Spectrum Supportability Risk Assessment (See DoDI 4650.01 and CH 3–4.3.20.)
  • Life-Cycle Mission Data Plan for Intelligence Mission Data (IMD)-dependent programs (See CH 3–4.3.12. Intelligence (Life-Cycle Mission Data Plan) and CH 7–4.1.3.)

Systems Engineering Activities in O&S Phase

Reference Source: DAG CH 3-3.2.6 Operations and Support Phase

The O&S phase overlaps with the Production and Deployment (P&D) phase, since O&S activities begin when the first system is deployed. O&S ends when a system is demilitarized and disposed of. Figure 18 provides the end-to-end perspective and the integration of SE technical reviews and audits across the acquisition life cycle.

Visual of weapon system lifecycle events

Figure 18: Weapon System Development Lifecycle

SE activities should be integrated with O&S phase-specific test and evaluation and logistics and sustainment activities identified in CH 8–4.5. and CH 4–3.5., respectively. The O&S activities in which the Systems Engineer should participate include:

  • Updating risk, issue and opportunity plans. Identifying, analyzing, mitigating, and monitoring risks and issues; and identifying, analyzing managing and monitoring opportunities. (See the DoD Risk, Issue, and Opportunity Management Guide for Defense Acquisition Programs).
  • Addressing problem/failure reports through the use of a comprehensive data collection approach such as a Failure Reporting, Analysis and Corrective Action System (FRACAS).
  • Processing and analyzing mission data.
  • Managing preplanned product improvements (P3I) and assessing the impact of system requirements changes resulting from evolving threats, changes to operational environment or in response to changes within the SoS or interfacing systems.
  • Making changes to the system technical baseline to maintain it as the authoritative source; changes may be due to PCAs, ECPs or changes to interfaces to external systems.
  • Developing and implementing technology refresh schedules.
  • Conducting technology insertion efforts as needed to maintain or improve system performance.
  • Updating system safety assessments.
  • Performing engineering analysis to investigate the impact of DMSMS issues.
  • Working with vendors and the general technical community to determine opportunities for technology insertion to improve reliability and affordability.
  • The disposal activities in which the Systems Engineer should participate include:
  • Supporting demilitarizing and disposing of the system; in accordance with all legal and regulatory requirements and policy relating to safety (including explosives safety), security and the environment.
  • Documenting lessons learned.
  • Archiving data.

Systems Engineering Outputs and Products

Reference Source: DAG CH 3-3.2.6 Operations and Support Phase

  • Safe, sustainable and reliable system that meets operational needs
  • Trade-off analysis results
    • O&S phase trade studies support system modifications and/or disposal efforts
  • Assessment of technical risk (See CH 3–4.1.5. and the DoD Risk, Issue, and Opportunity
  • Management Guide for Defense Acquisition Programs.)
  • Interdependencies/interfaces/memoranda of agreement (MOAs)
  • Information Support Plan (ISP) of Record (See CH 6–3.8.)
  • In-service performance and failure data
  • Value engineering results, as appropriate (See CH 3–2.4.4. Value Engineering)
  • Engineering Change Proposal (ECP) packages

Cost Estimation in O&S Phase

Reference Source: DAG CH 2-2.1.4 Operating and Support

Post-initial operational capability (IOC), DoD Components must continue to track operating and support (O&S) costs and update O&S cost estimates yearly throughout a program’s life cycle to determine whether preliminary information and assumptions remain relevant and accurate and to identify and record reasons for variances.

O&S cost estimates are independently reviewed at post-IOC reviews. Each O&S cost estimate must be compared to earlier estimates and the program’s O&S affordability caps, and, as appropriate, used to update the life-cycle affordability analysis provided to the MDA and requirements validation authority. This comparison must identify the reasons for significant changes and categorize those reasons into external and internal ones.

CAPE provides guidance on O&S cost estimating in its Operating and Support Cost Estimating Guidebook.

T&E Considerations

Reference Source: DAG CH 8-4.5 Operations and Support Phase

The operations and support (O&S) phase focuses on executing the product support strategy, satisfying materiel readiness and operational performance requirements, and sustaining the system in the most cost-effective manner over its total life cycle (including disposal).

O&S has two major efforts: life cycle sustainment and disposal. Effective sustainment of systems results from the design and development of supportable, reliable, and maintainable systems. Sustainment strategies can evolve throughout the system’s life cycle. The PM works with system users to document performance and sustainment requirements in agreements specifying objective outcomes, measures, resource commitments, and stakeholder responsibilities. The Services, with system users, conduct continuing reviews of sustainment strategies to compare performance expectations against actual performance measures. The program disposes of the system in an appropriate manner when it reaches the end of its useful life.

Sustainment Considerations

Reference Source: DAG CH 4-3.5 Operating and Support Phase

The Operating and Support (O&S) phase is the culmination of the sustainment planning done in the previous phases. During this phase, the PM is focused on supporting the Warfighter’s operations and training by executing the sustainment strategy, monitoring the performance of the system, assessing the effectiveness and affordability of the product support strategy, and making adjustments to the product support package.

LCSP Focus
  • Sustaining engineering processes for refining product support package elements
  • Logistics assessments on how the system and supply chain are performing
  • Adjustments required for program or funding changes


In the O&S phase, the PM monitors product support performance against sustainment metrics and takes corrective action if needed. The product support package is refined and adjusted based on performance, evolving operational needs, and improvement initiatives. PMs ensure that support systems and services have been delivered and depot maintenance is being performed as outlined in the LCSP.

PMs should revalidate their program’s product support strategy and ensure that it still meets suitability and affordability requirements. Indeed, 10 USC 2337(b)(2)(g), requires a revalidated BCA when the product support strategy is changed, or every five years, whichever comes first. PMs should continually monitor and assess the sustainment strategy’s suitability, particularly regarding changes in operating conditions or program assumptions. The PM also helps inform the life extension and disposal decisions, although the PM is not the decision authority. Additionally, incremental development of systems may require multiple configurations or blocks of a weapon system, and the product support strategy should reflect these requirements.

The PM tracks and reports supply chain performance and its effectiveness. Tracking should include the sustainment metric drivers in the supply chain and the root cause of performance shortfalls. Special emphasis is placed on tracking the drivers for the key enabler technologies that most impact Am.

PMs also work closely with their PSIs or supply support activities to monitor the health and efficiency of the supply chain. The risk of Diminishing Manufacturing Sources and Materiel Shortages (DMSMS) increases over time, and the PM should monitor this through annual assessments of the supplier base health.

The PMs input during this phase focuses on cost estimates and funding requirements necessary to sustain the fielded systems and meet training and operational readiness requirements within affordability constraints. Specific inputs include funding requirements related to replenishment spares and support equipment, hardware and software depot maintenance, modifications, system safety investigations, etc. Other logistics and sustainment-related funding considerations for the program include those needed to conduct post-fielding reviews, execute a technology refreshment program, ensure system security, and provide for resource sustainment contracts and service-level agreements.

After IOC, Should Cost Initiatives may reflect O&S Cost drivers highlighted during operation and use of the system. This is also the time for the PM to evaluate whether the prior O&S Should Cost initiatives have produced the expected savings.

The PM’s role in the Cost and Software Data Reporting (CSDR) process is to work with the cost estimators and contracting professionals to ensure that the CDRLs are included in sustainment contracts beginning with the development of the RFP through the signing of the contract.

As part of Sustainment Reviews during O&S, the PM ensures that sustainment performance of fielded units has been continually assessed and all service-use data (e.g., readiness degraders, changes in operational usage or environment, material failures, hazard reports, etc.) have been collected, analyzed, and assessed for operational and safety risks.

Reference Source: DAG CH 4-4.8

Modification Programs

During the O&S phase, a program may require modifications to meet emerging requirements, improve performance, address safety issues, reduce operating costs, or extend operational life. Additionally, modern acquisition programs are dependent on technology and thus may require technology refresh and insertion at a higher rate than legacy systems. Across DoD, the definition of modification varies from the replacement of a component to an MDAP-sized investment.