Per FAR Subpart 237.2, all of the various types of ETS are considered by DoD to be A&AS. Each Service's technical assist programs vary somewhat, but they all include the goals of improved program and project management of DoD systems or programs through advice, assistance or training. This can include program monitoring, resource management, planning, and programming, and milestone and schedule tracking. Advice for the efficient and effective operation of fielded weapons, weapon support and communication systems, equipment, or components can include assisting in the introduction and transfer of engineering and technical knowledge for fielded systems, equipment, and components.  This assistance is often in the form of organic support, or it can be via contracted technical representatives. Contracted A&AS (CAAS) personnel are typically used when suitable in-house capability is unavailable or cannot be obtained in time to meet the needs of the DoD Component, or if it is not cost-effective to establish organic capability. CAAS should not be used for inherently governmental functions, nor to bypass personnel ceilings or competitive employment procedures.

ARMY – AR 700-4, provides policy and organizational structure for the Army Logistics Assistance Program (LAP). LAP is run by Army Sustainment Command (ASC) as part of Army Materiel Command (AMC). The LAP is oriented to the early detection and resolution of logistics related problems that affect unit and materiel readiness, and for making logistical assessments in coordination with the supported commands to determine current status, historical trends, and providing corrective and preventative measures for improving unit and command readiness. This includes identification and correction of systemic problems.

LAP provides support to units in garrison, and also in conjunction with deployments for exercises, natural disasters, contingencies and war. The LAP offers commanders a single AMC point of contact for all logistics and technical issues, including:

• Providing technical guidance necessary to resolve weapon systems, equipment, and systemic logistics problems
• Identiying and reporting on logistics issues that have an adverse impact on logistics readiness, including supply, maintenance, transportation, personnel, training, organization, systems, doctrine, etc.
• Collecting and assessing logistics related data
• Providing a single POC and conduit between the warfighter and AMC
• Providing expert personnel in system issues such as readiness and supply functions, and mechanical, electronic and electrical systems experts knowledgeable in the entire range of deployed Army systems

AR 700-4 includes the process and details for LAP personnel management, including uniforms, transportation, recruiting and physical requirements, assignments, record keeping, and more.  It also includes procedures to access Contractor Engineering and Technical Services (CETS) should organic support from LAP be unavailable, insufficient, or inappropriate. CETS is often used during initial transfer of engineering and technical knowledge, during an initial weapons system deployment, and can cover installation, operation, and maintenance of weapon systems, equipment, and components. The Army recognizes three types of CETS:

1. Contractor plant services are those engineering and technical services provided to Army personnel by a manufacturer. These services are provided in the manufacturer’s facilities by engineers and technicians employed by the manufacturer.
2. Contract field services (CFS) are those engineering and technical services provided to Army personnel by technically qualified contractor representatives. These are generally one-time services such as those provided in the hand-off of equipment, and include information, instruction, formal training, and on-the-job training, provided at an Army installation or materiel fielding hand-off site.
3. CFS are those employees of a manufacturer or supplier of military equipment or components who provide full-time on-site liaison or advisory services between their company and the military users of their company’s equipment or components. AR 700-4 places limitations and timelines on use of CETS and tasks AMC with program management, to facilitate switching to LAP at the earliest point when the option makes sense.

AMC, in conjunction with ASC or Life Cycle Management Commands (LCMC), will annually develop LAP manpower requirements based on unit requirements, in a manpower requirements package for upcoming fiscal year. Per chapter 4 of the AR 700-4, commanders having short-term or emergency requests for assistance, not part of the annual planning manpower documents, will notify their area chain of command and submit requirements to AMC, with complete specifics on the requirement, and comprehensive justification of need.

AIR FORCE – AFI 21-101 authorizes ETS programs to help ensure Air Force units can maintain weapons systems and equipment to meet operational needs at reasonable cost. The ETS program includes both CETS and Air Force ETS (AFETS). AFETS field engineers are the primary source of ETS support in the Air Force, and should be used and retrained as necessary to meet technical needs. CETS are important elements in developing an independent Air Force capability on new systems; however, units must develop their own organic and AFETS capability whenever possible. The two programs are both managed by Air Force Headquarters. AFI 21-110 provides details about ETS funding, assignment, training, physical requirements and other personnel issues.

AFETS field engineers are highly experienced and thoroughly trained civilian technical specialists. AFETS are typically limited to civilians because of the advantages of long-term continuity and decreased retraining costs provided by a civilian work force. They help units and Major Command (MAJCOM) functional managers in resolving complex system problems. They assist in troubleshooting and repairing critical maintenance problems and research, analyze, and provide solutions for long-term and Air Force-wide support equipment problems. AFETS design special test equipment, develop special maintenance procedures, develop and conduct technical training for unit maintainers and operators, and recommend changes to maintenance processes, all in coordination with the cognizant engineering authority. AFETS also serve as the unit technical liaison and work with MAJCOM functional managers, depot technicians, engineers and item managers, and equipment manufacturers to resolve equipment problems.

CETS and AFETS are requested annually, with specific requirements and narrative justifications as described in attachments to AFI 21-110. Urgent, out of cycle requests require more detailed justification, but may be submitted as required. Out-of-cycle requirements must show why the requirements were not included in prior year programmed submissions and reasons why the unit is unable to perform services with in-house resources. Requests for CETS less than 150 days before the start date for the service are emergency procurement actions requiring MAJCOM approval. The unit initiating requests for such services must follow separate criteria and forward the information necessary to justify the emergency action(s) to the chain of command.

NAVY/MARINE CORPS – Per SECNAVINST 5400.15, Navy System Commanders (Naval Air Systems Command or NAVAIR; Naval Sea Systems Command or NAVSEA; Naval Information Warfare Systems Command or NAVWAR; and Marine Corps Systems Command, or MCSC) are responsible for providing for in-service support; providing support services to Program Executive Officers (PEO) and Direct Reporting Program Managers (DRPM) without duplicating their management functions; and serving as the technical authority and operational safety and assurance certification authorities for their assigned areas of responsibiliities  

Naval ship ETS are provided through Naval Sea Logistics Center (NSLC), which is part of the Naval Sea Systems Command (NAVSEA). Aviation related requirements are handled by Naval Air Technical Data and Engineering Center (NATEC) , part of Naval Air Systems Command (NAVAIR), and the most common provider for ETS for Navy and Marine Corps aircraft, and other non-ship equipment and systems. (The NATEC website provides multiple process and guidance documents, but is accessible only with special access.)  NATEC provides field level engineering technical advice, assistance, instruction, and training to aviation activities in the installation, maintenance, repair and operation of aviation airframes, systems and associated equipment. In addition for both shipboard and aviation platforms the associated depot or Fleet Readiness Centers (FRC) operate In-Service Support Centers (ISSC) with flyaway teams for the systems supported to offer forward deployed training, maintenance and logistics assistance. In practice it is often the ISSCs that provide tech assists for non-aviation systems, while for Navy and Marine aviation commands, NATEC is likely the primary source for engineering technical services.

Engineering technical assistance is requested via message to NATEC via the Commander, Naval Air Force Atlantic (COMNAVAIRLANT) chain of command. For non-deployed commands, requesting organizations will make the request via the ETS Local Assistance Request (ELARS) through the NATEC website.  NATEC will coordinate requests for assistance with the requestor’s supporting FRC, Marine Aircraft Group (MAG), or Marine Aviation Logistics Squadron (MALS), to provide ETS in the most expeditious manner and from the most appropriate source. On-call support personnel may come from the FRC, from NATEC, from NAVSEASYSCOM via the NSLC, or even industry.