Army Materiel Systems Analysis Activity Tackles Safety and Cost Savings
The Army Materiel Systems Analysis Activity (AMSAA), located on Aberdeen Proving Ground, conducts analyses across the Materiel Lifecycle to inform critical decisions for current and future soldier needs. AMSAA is engaged across the Army and Department of Defense (DoD) to provide analytical solutions to the most challenging reliability problems.
The U.S. military has many great systems to defeat any adversary. As the U.S. armed services become even leaner, the reliability of this equipment becomes a greater factor in the military’s success. Poor reliability of equipment leads to higher costs for replacement parts and maintenance. On average, over 60 percent of a system’s total life cycle cost is tied up in sustainment [McQueary, NDIA SE Conference, 2007]. Fielding more reliable equipment not only benefits the soldier in the fight, but also lowers the operations and support costs across the DoD on the order of billions of dollars.
The commercial sector also has this same reliability challenge. In the recent past, there have been numerous high-profile incidents involving ignition switches, air bags and video game consoles. The key is to leverage the best solution sets across the DoD and industry to improve reliability and save costs. Three of these solutions sets can be characterized as Design-for-Reliability, Reliability Risk Management and Reliability Growth.
Design-for-Reliability applies thermal, vibrations and shock engineering analysis techniques to identify failure modes early during the system development process. The cost of fixing issues early is small. The cost to address failures once the design has been locked or the product has been fielded is enormous. AMSAA has worked with Army partners to Design-for-Reliability. Two examples are highlighted below; a military tracked robot and an electronics board for a soldier device.
The tracked robot is used for military operations in urban terrain. Modeling and simulation simulated the robot’s potential impact events from various drop heights and orientations in a controlled manner. As shown in Figure 1, the simulation of the robot’s wheel deformation accurately replicated a real-life test of the impact event. Design changes to improve reliability can be analyzed and verified using the modeling and simulation, leading to substantial test cost savings in the millions of dollars. Modeling and simulation, in conjunction with testing, provides increased confidence through a greater understanding of system behavior and consequences of that behavior.
Figure 1. Wheel Deformation Comparison: Model (Top) vs. Prototype Wheel (Bottom)
An electronics board for a Soldier device is subjected to significant levels of vibration during operation. To find weak spots in the design, the board can be modeled for vibration effects, as shown in Figure 2. For this specific board and its mounting configuration, the modeling showed that the middle of the board had damaging levels of vibration with the basic 4-screw mounting configuration. This model made it simple to consider different mounting configurations and their associated impacts on the vibration levels. The analysis concluded that adding two strategically placed screws significantly dampened the vibration profile, preventing failures from occurring. The cost of this slight design modification was minimal, but it had significant cost-saving ramifications.
Figure 2. Vibration Effects on an Electronics Board
Reliability Risk Management, the second solution set, addresses the elements of a program associated with reliability during system development. Is the developer using strong Design-for-Reliability techniques? Does the developer have a good handle on their parts suppliers? Is there sufficient reliability testing built into the schedule? Characterizing risk areas and identifying gaps early in development allows time for any deficiencies to be remedied. Furthermore, by holding the developer accountable and ensuring good reliability practices are being followed, it is more likely that a reliable system is produced and delivered to the soldier.
The AMSAA Reliability Scorecard is a risk management tool that examines the reliability practices and tasks employed by the program’s contracted industry developer. It is comprised of 40 elements covering eight categories. Using information about the system developer’s history and business practices, these elements are assessed with a low, medium or high-risk score based on the provided criteria. These scores are weighted to end up with an overall system risk score, as shown by the sample output in Figure 3. The Reliability Scorecard can be applied at any point in development. If applied early enough, programs with a medium or high-risk score may be able to firm up the deficient areas in order to design, test, and produce a more reliability system.
Figure 3. Sample Reliability Scorecard Output
The third solution set, Reliability Growth, is defined as the improvement of reliability over time. Reliability growth testing is used to find those issues still remaining in the system after the up-front design work. Reliability growth occurs during this testing as failures are observed and fixed with design modifications. The rate of reliability growth will depend on the number of failures fixed and the effectiveness of those fixes. Both the DoD and industry have models, many produced at AMSAA, that aid in planning for reliability growth, tracking reliability growth, and projecting future reliability growth.
Reliability growth planning models are used by many Project Managers (PMs) to plan for and manage reliability growth during testing. How many items should be tested? How will the test schedule fit into the over-arching program schedule? How many failures are expected in each of the test events? Reliability growth planning models encourage PMs to consider these elements early in development. A good reliability growth plan has built-in checks on progress toward reliability goals. As testing progresses, the test data is used to track actual reliability growth vs. the plan, indicating when there are shortfalls. Figure 4 shows a sample reliability growth-planning curve, illustrating the expected path of reliability growth through testing and fixing observed failures.
Figure 4. Sample Reliability Growth Curve
Design-for-Reliability, Reliability Risk Management and Reliability Growth are key elements to any successful developmental program. AMSAA will continue to expand on these solution sets that help to improve the reliability of our military systems. Without a doubt, better reliability of equipment increases soldier confidence. High reliability also reduces operation and support costs so the United States can afford to keep investing in the technological advancements that make the U.S. military the strongest in the world.
The Army Materiel Systems Analysis Activity (AMSAA) is a Separate Reporting Activity to the U.S. Army Materiel Command. AMSAA is comprised of approximately 300 civilian analysts, engineers, and scientists. AMSAA’s primary mission is to conduct analyses across the Materiel Lifecycle to inform critical decisions for current and future Soldier needs while valuing the unique knowledge, experiences, and backgrounds of its people. For further information about AMSAA, visit www.amsaa.army.mil. I95