BIT/BITE/ED/EP/IVHM and ATE in DA

Willis H. Yarnall, Charles R. Moore, Phil L. Dussault Engineering Support Division

Engineering Directorate, AMRDEC Redstone, AL USA

Abstract—Automatic test equipment (ATE) in the Department of the Army (DA) finds itself in an ever challenging and changing role in an effort to support the Future Force of the 21st century. Challenging in that the ATE today must combat obsolescence while supporting both the legacy and future systems; and changing in that Army Transformation is transitioning from four (4) to two (2) levels of maintenance support. Advances in technology in the areas of built-in-test (BIT), built-in-test equipment (BITE), embedded diagnostics (ED), embedded prognostics (EP) and integrated vehicle health management (IHVM) have been the primary enablers allowing the DA to make major changes in maintenance, test philosophy and logistics in order to reduce cost, schedule and time. BIT/BITE/ED/EP/IVHM and ATE complement one another and each play a valuable and vital role in the maintenance and logistics support of the Future Force.

I. INTRODUCTION This paper presents the results of a study of built-in-test

(BIT), built-in-test equipment (BITE), embedded diagnostics (ED), embedded prognostics (EP) and integrated vehicle health management (IHVM), Automatic test equipment (ATE) and the status and role of each in the support of the Army in Transition. BIT/BITE/ED/EP/IVHM (herein refer to as simply ED/EP) and ATE in the Department of the Army (DA) and industry are essential to provide maintenance support for complex weapon systems. Advances in technology have allowed the weapon system design to become more modular with simple-to-replace components and line replaceable units (LRUs), include ED/EP capability, require less skilled maintenance personnel at the field level and have allowed the DA to transition from four (4) to two (2) levels of maintenance support. ED/EP and ATE complement each other and as indicated by Reference [1], both will be required to support the Army in Transition until weapon systems are capable of self-repair.

II. OFF-PLATFORM ATE TODAY ED/EP and ATE in the DA and industry are essential to

provide maintenance support for complex weapon systems. Advances in technology have allowed the weapon system design to become more modular with simple-to-replace components and line replaceable units (LRUs), include ED/EP capability, require less skilled maintenance personnel at the field level and have allowed the DA to transition from four (4) to two (2) levels of maintenance support. The increasing

complexity and component density of electronic systems, as well as the decline in the numbers of trained technicians, are leading to increased reliance on automation in maintenance [2]. Current ATE is challenged and driven by obsolescence issues, advances in semiconductor manufacturing technology, the need for reduction in test time and cost, and a migration toward an open architecture test system to meet these challenges [3,4,5].

The DA has designated that the Integrated Family of Test Equipment (IFTE) general purpose automatic test system (ATS) as the Army standard. The Next Generation Automatic Test Station (NGATS), when approved, will become the latest member of the IFTE for the Army and utilizes state-of-the-art commercial-off-the-shelf (COTS) test instruments and open-system architecture [6].

The DA is transitioning from four (4) to two (2) levels of maintenance support (the unit and direct levels of maintenance will be combined and called “field maintenance and the general and depot levels will be combined and called “sustainment support”). Field maintenance will be characterized by “on-system maintenance” and sustainment maintenance will be “off-system maintenance.” Field maintenance will be repair and return to user; sustainment maintenance will be repair and return to supply [7]. In the Expeditionary Army modular organizational concept, the off-platform ATE will be employed at the sustainment level [1]. The Army Transformation is updating its troop structure and plans with the Brigade Combat Team (BCT) Modernization plan built on a network enabled force that employs mobility and information sharing [8,9].

III. AT-PLATFORM ED/EP TODAY The goal of ED/EP systems is to provide a uniform body of

knowledge of the health state from which all of the user needs can be met, … include the faults, loss of functionality, degradations, incipient faults and predictions of progression of conditions [10]. Further, the functional foundation of ED/EP is highly integrated into the vehicle, its constituent subsystems, and the supporting ground based infrastructure [11]. ED/EP architecture supports both onboard and offboard components, and includes interfaces into the overall support (e.g., maintenance and logistics) system, subsystem/vehicle controls, and mission/operations management [12].

At-platform test capabilities are incorporated concurrent with hardware design and the success of the ED/EP is dependent on the skill and capability of the designer. A well-designed ED/EP system can substantially reduce the need for

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trained field-level maintenance personnel by permitting less skilled personnel to locate failures and channel suspect equipment to centralized workshop repair facilities that are equipped to repair defective equipment [13].

ED/EP has proved useful when failure occurrences were uniquely associated with the operating environment [14], has historically been used for in-field maintenance by the end user, has been used to indicate system status [15], and to indicate whether a system has been assembled properly.

IV. DA POSITION RELEVANT TO AT-PLATFORM TEST FACILITIES AND OFF-PLATFORM ATE

DA policy mandates that Program Executive Officers (PEOs) and Product Managers (PMs) will work closely with the user community translating and incorporating diagnostics and prognostics requirements found in the requirements document into system specifications and contract requirements [16] and that PMs, through their PEOs, will coordinate their strategy for acquiring embedded diagnostics (built-in-test) with the product manager of U.S. Army Test, Measurement, and Diagnostic Equipment (TMDE) activity [17].

A comprehensive diagnostic and prognostic capability for electronic system components builds upon enabling technologies such as built-in-test, advanced health monitoring algorithms, reliability and component aging models, prognostics methods… links between onboard, at-wing and depot test system [18].

The ATE test program set (TPS) must have the capability to capture and analyze the results of the ED/EP [19].

V. DA POSITION ON PERFORMANCE BASED LOGISTICS (PBL)

The DA strives to provide weapon system support in the most cost effective manner. The Quadrennial Defense Review (QDR) and the Defense Planning Guidance (DPG) directed the application of PBL to new and legacy weapons systems. PBL Implementation is mandated by DoD Directive 5000.1, The Defense Acquisition System, May 12, 200 [20]. Application of PBL guidance as a product support strategy is based on determination of the provider’s product support capability to meet set performance objectives. The focus is on buying a predetermined level of availability to meet war fighter objectives [20].

A formal decision to adopt a PBL product support strategy should require a completed, tailored Business Case Analysis (BCA). A PBL BCA provides the best-value analysis, considering not only cost, but other quantifiable and non-quantifiable factors support an investment decision [20].

DA’s weapon system support comprises a combination of public (organic) and private (commercial) support sources. Finding the right mix of support sources is based on best value determinations of inherent capabilities and compliance with statutes and policy. This process will determine the optimum PBL support strategy within the product support spectrum, which can range from primarily organic support to a total system support package provided by a commercial Original

Equipment Manufacturer (OEM) [20]. Thus, source of support decisions for PBL do not favor either organic or commercial providers but are based on best value.

VI. FUTURE REQUIREMENTS OF AT-PLATFORM TEST FACILITIES IN DA

Built-in test facilities, in particular built-in test equipment,

must be defined taking into consideration not only of price/performance aspects but also of their impact on the reliability and availability of the equipment or system in which they are used [21].

Built-in facilities should have a failure rate of at least one order of magnitude lower than that of the equipment or system in which they are used; their failure should not influence the item’s operation [21].

ED/EP are key enablers in the reduction of test time for weapon systems. ED/EP have been designated as key enablers for logistics transformation. A common vision for future logistics processes is that they are enabled by self-reporting platforms with ED/EP [22].

VII. FUTURE REQUIREMENTS OF OFF-PLATFORM ATE IN DA The off-platform Army ATE in DA is in a state of

transition: modular brigades; two level maintenance; emphasis on embedded diagnostics for legacy and future systems; and dynamic budget shifts effect maintenance landscape [20].

Army ATE will support both legacy and future systems during Army transition and will be located at the sustainment level in the Future Force. Future Force ATE must be a network-centric capable system [6] capable of communicating on-system failure information to repair facility and maintaining historical data for use to influence repair actions and weapon system upgrades. Support of legacy systems will continue to be supported in the manner they were intended from their inception through the end of their useful life-cycle or planned upgrades will incorporate enhanced technology. The legacy systems will diminish, by attrition, to the point that they will no longer remain in the inventory. Additionally, future ATE should migrate toward open architecture, COTS, reduced footprint, DoD common and networked information system [23].

VIII. SUMMARY OF AT-PLATFORM TEST FACILITIES The properties [21] include: monitoring of all important

functions and automatic display of complete and partial faults and performed with built-in means (ED/EP). The advantages are: runs automatically, i.e. in background and tests functionality. The disadvantages are: expensive, increases footprint and degrades reliability.

IX. SUMMARY OF OFF-PLATFORM ATE The properties [21] include: periodic testing of all

important functions and testing initiated by operating personnel, then runs automatically or semi-automatically (possibly without external stimulation or test equipment).

The advantages are: gives a clear status of the functional conditions of the unit under test (UUT), tests in accordance with performance specification and allows fault isolation down to the assembly level (SRU, circuit card assembly, component, etc). The disadvantages are: relatively expensive and runs generally off-line (i.e. not in the background).

X. ED/EP ROLE ED/EP should identify weapon system LRU status and

identify failed shop replaceable unit (SRU) at platform.

ED/EP data should ‘mesh’ with TPS to provide ‘smart TPS,’ reduce ATE/TPS test time, development cost, allow utilization of less skilled personnel at the field level and are not fully mature until some time after fielding [24]. ED/EP success is dependent upon the skill and knowledge of the designer. The suitability and effectiveness of ED/EP must be judged in terms of its ability to meet the desired objectives [14]. The embedded systems have diagnostics capabilities that autonomously isolate faults in mission-critical systems to the line-replacable unit (LRU) or major component level [24]. Many of the embedded systems have prognostics capabilities allowing them to predict failures in key systems in advance of the actual failure to allow for scheduling of corrective maintenance actions and distribution of required repair parts [24].

XI. ATE ROLE ATE verifies the ED/EP functionality, complements and

supports the same. ATE provides the capability to verify the ability of UUT to meet performance specification and fault isolate to the assembly level (SRU, circuit card assembly, component, etc). ATE/TPS ensure the availability of the Army’s weapon systems by providing diagnostic and test capability that enables the repair of the faulty system components [6].

Diagnose and fault isolate LRUs to the SRU level [25] and beyond. Screen for no-evidence-of-failure (NEOF) to reduce the rate of LRUs sent back to the depots that are NEOF [25]. Ensure user-friendly reconfiguration to provide support for multiple weapon systems [25].

XII. IN RETROSPECT Advances in technology have produced improved ED/EP

which reduce ATE test requirements, costs, permit the use of less skilled repairmen in the field and have been enablers to allow the DA to restructure maintenance and logistics support under the Army Transformation Plan. ED/EP have been the primary enablers of the embedded diagnostics and prognostics synchronization (EDAPS) effort and the implementation of two level maintenance support. The EDAPS is occurring concurrently with the ongoing fielding of the Stryker Brigade Combat Teams (BCT). As part of the EDAPS effort, the U.S. Army Logistics Transformation Agency (USLTA) established a BCT Proof of Enablers Demonstration to integrate and test the key enablers required to initiate implementation of the Common Logistics Operating Environment (CLOE) [22].

CLOE describes the Army’s vision for developing a technology-enabled force equipped with self-diagnosing

equipment platforms that interact with a networked sustainment infrastructure to support conditioned-based maintenance and accelerate implementation of Future Force logistics processes. CLOE focuses on the Future Force [22].

ED/EP is not a stand-alone capability on combat platforms. The potential benefits from this enabler can only be achieved if it is integrated with other enablers and the many off-platform communications, command, and control and management information systems that will provide the diagnostic and prognostic information to users and revolutionize the logistics support structure for the future. The objective of this logistics effort is to allow for just-in-time resupply [22] or right part, right place, right time.

The IFTE has been designated as the standard ATS of the DA. The DA is meeting challenges presented by obsolescence, cost and enhanced technology that ATE faces today with the development of the NGATS. The NGATS utilizes state-of-the-art COTS test instruments and open-system architecture. The NGATS is net-centric capable system with and enhanced data capture and analysis capability, can capture and share component failure data throughout the supply chain [6]. This capability fulfills the requirement of the Future Force ATE to collect, record and forward output/failure data to a central point for analysis and further use, e.g. project failure or trigger the supply chain. Once again, another example of how ED/EP and ATE complement one another.

DA policy mandates that PEOs and PMs will work with the user to interpret and incorporate the diagnostics and prognostics found in the requirements documents into the system specifications. Policy further mandates that PMs, through their PEOs, will coordinate their strategy for acquiring ED/EP with the product manager of TMDE. ED/EP must be defined taking into consideration not only of price/performance aspects but also of their impact on the reliability and availability of the equipment or system. The extent to which ED/EP is utilized should be resultant of a business case analysis of these factors, as well as, footprint.

In October 1999, the Army announced a priority program to transform into a force that could better meet future requirements to be both rapidly deployable and lethal. The first step was near-term fielding of a new unit, first called the Interim Brigade Combat Teams but later called the Stryker Brigade Combat Team (SBCT). For the long term, the Army would be developing a Future Combat System (FCS) based on new technologies that would equip very mobile formations with lethality and survivability equal or greater than that of present heavy units [26]. An acquisition decision memorandum (ADM) issued June 24, 2009 by the Under Secretary Of Defense for Acquisition, Technology and Logistics Secretary Robert Gates cancelled the Future Combat Systems Brigade Combat Team (FCS BCT) program and directed the Army to transition to a modernization plan consisting of a number of separate but integrated acquisition programs to meet the secretary’s objectives [27]. The Army transformation plan outlining desired current and future capabilities is detailed in the Army transformation roadmap which articulates a multi-year plan that focuses mainly on improving the Current Force from 2004-2010, then gradually

transition the focus on building the Future Force in the following years [9].

XIII. CONCLUSIONS The Army modernization plan takes advantage of advances

in technology and prepares the Future Force to better meet current and future threats. ED/EP and ATE play vital roles in the maintenance and logistics support of the Legacy and Future systems and Current and Future forces. No matter how a faulty weapon system is diagnosed at the platform, there will be a requirement to repair the component, unless deemed nonreparable. Even as systems move to become more self-diagnosing through embedded diagnostics and prognostics, until those same systems become self-repairing, ATE will be required to provide organic support for system component diagnostics and repair [6].

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