The total cost of ownership for any system starts accumulating at its inception and completes when the last system is disposed of - “from inception to grave.” To control or minimize these costs, the inception and design phase must be thoroughly thought out. Designs and maintenance costs are fairly well "locked in" during the design phase and the costs to correct any deficiencies become more and more costly as the systems age. The factors to consider in the design phase, so as to minimize the costs of ownership, include design costs, manufacturing costs, operational costs, and disposal costs.

In the aviation community, the ability to maintain costs and lengthen the life of systems is an ever increasing requirement. To achieve long life, the ability to interject pre-planned product improvements, P3I, is a critical factor that must be defined in the design stage and must be followed during the operational phase of any program. An example of an aircraft that achieved a long life due to a pre-planned product approach was the Northrop Grumman F-14.
In the design phase of the F-14, planned upgrades in power plants and electronics allowed for additional capabilities to be incorporated without major airframe redesign. As illustrated in the images above, the original cockpit allowed sufficient space to bring in new displays, controls and switches required to support advancements in air warfare. On the other hand, the A-4 Skyhawk was subjected to several major airframe changes to accommodate upgrades that were not planned nor scheduled during the design phase. As illustrated in the photographs of the A-4 Skyhawks on the previous page, the addition of the “hump” in the A-4M was required to contain electronics and controls which the original airframe could not contain.

A major driver controlling Operational Availability, AO, in aging aircraft is the electronics. As the age of the aviation fleet is extended, the ability to return electronic assemblies to service is impacted by parts and manufacturing techniques that may not be available. This has created the need for assembly cannibalization and costly partial redesigns that create excessive costs to the using organization.

How can the cost of maintaining systems be controlled and minimized? Incorporating the systems engineering techniques at the program inception is best - incorporating the systems engineering concepts during the operational stage is mandatory. Systems Maintenance Costs are comprised of the following categories:

Level of Maintenance Support. Determine the sparing levels, maintenance personnel capabilities, and type of equipment available to perform the maintenance.

Repair Policy. Where are the locations of the various repair centers (operational, intermediate and depot)? Is the maintenance performed by the owner or manufacturer? What is the scrap/repair policy, and where are the spares located?

Responsibility of Support. Detail of diagnostic capability (Built in Test, BIT), accessibility, and readily removable functional package must be determined.

Major Elements of Logistics Support. Standard test interface, test database requirements, training of maintenance personnel, and test philosophy should be established.

Effectiveness Requirements. Mean time to repair (MTTR), frequency of scheduled maintenance, mean time between failures (MTBF), and administrative down time for logistics (ADTL - the time required to receive a spare part once ordered) are all major drivers to the size and therefore the cost of the spares pool.

Maintenance Requirements. Skill level of maintenance personnel, calibration facilities, and facility requirements should also be established.
Regarding the maintenance development plan for aviation, the Aircraft Manufacturers Association Maintenance Planning Document (MSG-3), helps establish a logical progression to a maintenance and replacement policy. For Naval Air Systems, the governing documents that help establish the maintenance plan and redesign considerations are MIL-STD-2173 Reliability-Centered Maintenance Requirements for Naval Aircraft, Weapons Systems & Support Equipment.

ACI is re-engineering the C-6533 intercom for CECOM as well as providing support for the testing and analysis of the replacement gyro for the H-60 and H-47 helicopter fleet. ACI is also supporting NAVAIR Aging Aircraft in failure analysis, parts obsolescence and the desire to extend aircraft life and maintenance costs.