Product Support is the application of the package [called Product Support Package (PSP)] of integrated logistics elements and support functions necessary to sustain the readiness and operational capability of a system. It includes the logistics elements of manpower and personnel, technical data, facilities, maintenance planning, supply support, and computer resource support.
They must be integrated because they impact each other and Materiel Availability. During the Acquisition Process, the focus is on influencing the design for supportability and by fielding the Support Concept to satisfy user-specified requirements for sustaining system performance at the lowest ownership cost. This applies to each increment of the capability to be developed and is detailed in the Product Support Strategy.
Guidebook: DoD Product Support Manager Guidebook – June 2016
Features of Product Support Include: 
- Availability of support to meet Warfighter specified levels of combat and peacetime performance;
- Logistics support that sustains both short and long term readiness;
- Management of Life-Cycle Cost (LCC) through analysis and decision prioritization;
- Maintenance Concepts to integrate the logistics elements and optimize readiness while drawing upon both organic and industry sources;
- Data management and Configuration Management (CM) that facilitates cost-effective product support throughout the system life cycle;
- A Diminishing Manufacturing Sources and Material Shortages Management Process (DMSMS) that ensures effective, affordable, and operationally reliable systems;
- Operator and maintainer training to encompass the full capability of the system.
The Support Concept defines the overall logistics end state in achieving Product Support. The Program Manager (PM) establishes logistics support concepts (e.g., organic, two-level, three-level, contractor, partnering, etc.) early in the program, and refines the concepts throughout program development.
The Support Concept has to address the hardware and its associated software (including Commercial off-the-Shelf (COTS) software) since the software can be a major sustainment issue as systems become more software-intensive. Programs need to plan for technology refreshment and maintaining the software after production. This includes how changes (for obsolescence/ technology refreshment and maintaining the software) will be budgeted and executed along with the necessary technical data required to sustain the software throughout the system life. In addition to sustaining the software, aspects such as customer support, systems administration help desk support, etc. need to be considered. 
Achieving the support concept and sustaining operational capability requires the involvement of the logistics, engineering, testing, program management, contracts, supply chain, and financial management experts. The overall support strategy, documented in the Life-Cycle Sustainment Plan (LCSP), should include life-cycle support planning and address actions to assure sustainment and continually improve product affordability for programs in initial procurement, re-procurement, and post-production support. A performance-based product support process will be used to align the support activities necessary to meet these objectives.
Product Support Manager
The Product Support Manager (PSM) is responsible for managing the support functions required to field and maintain the readiness and operational capability of major weapon systems, subsystems, and components. They’re also responsible for accomplishing the overall integration of Product Support through government activities or via a contract with a commercial organization. The support functions the PSM need to manage related to weapon system readiness include: 
Product Support Strategy
The Product Support Strategy (PSS) is part of the Acquisition Strategy and addresses Product Support as in life cycle sustainment and continuous improvement of product affordability, reliability, and supportability. It ensures that system support and life cycle affordability considerations are addressed and documented (including the depot maintenance requirements and the implications of core requirements) and what is expected from each of the stakeholders. The PSS is detailed in the Life-Cycle Sustainment Plan (LCSP) which documents the plan for formulating, integrating, and executing the PSS (including any support contracts) to meet the warfighters mission requirements. The development of the product support strategy is detailed in the 12 Step Product Support Process Model. 
Integrated Product Support (IPS)
Integrated Product Support (IPS), use to be integrated logistics support (ILS), is a unified and iterative approach to the management and technical activities needed to influence operational and materiel requirements and design specifications for logistics support. IPS define the support requirements best related to system design and to each other, develop and acquire the required support, provide required operational support at the lowest cost, seek readiness and Life-Cycle Cost (LCC) improvements in the materiel system and support systems during the operational life cycle, and repeatedly examine support requirements throughout the service life of the system.
AcqLinks and References:
- Guidebook: Product Support Managers Guidebook – 24 June 2016
- DoD Instruction 5000.91 “Product Support for Adaptive Acquisition” – 4 Nov 2021
- Performance-Based Agreements Development Stages
- Defense Acquisition Guidebook (DAG) – Chapter 5.1.4
- Performance-Based Logistics: A Program Manager’s Product Support Guide
- Performance-Based Agreement Toolkit