Reusable Automated Platform SIL Testing - A Cost-Effective Risk-Reduced Process for Airworthy Reusable Software

Current and projected program requirements are exceeding Department of Defense (DoD) budget and schedule constraints. This applies to the Army’s requirements to integrate common avionics equipment onto dissimilar aircraft – both manned and unmanned. As such, innovative approaches and new acquisition business practices are needed to reduce platform integration costs and speed the fielding of important war-fighting capabilities. The Common Software Initiative (CSI) was formed by the US Army’s Product Manager of Aviation Mission Equipment (AME) to explore solutions to these problems. In support of CSI, Tucson Embedded Systems (TES) developed and is applying automated testing capabilities and performing the verification of an AME Alt-Comms reusable software product. TES acts as a third-party platform integrator testing the product prior to it being released to the Platforms. The integrator’s environment and automated testing capability supports the development and test phases and promotes the evaluation of embedded control software across a fleet of multiple dissimilar platforms prior to formal release. TES has developed a cost-effective risk-reduced automated test environment to support the development and integration of reusable aviation software for the US Army Aviation Systems. The planned goal is 100% reuse of automated testing software and testing artifacts, such that one piece of test software and accompanying artifacts may be certified once and reused across multiple platforms as described in the FAA Advisory Circular AC 20-148 [1]. The reuse and automation will reduce costly and time-consuming platform System Integration Laboratories (SILs) testing and will support the formal qualification testing (FQT) efforts of the software. With automated reusable testing, TES and PM-AME estimates a reduction of more than 70% time and more than 50% cost of integration (potentially 57%) when compared to current business practices. This would allow the DoD to field two to six additional capability sets for the same budget as one. While first applied and used to certify PM-AME’s reusable radio control software targeted for PM-Cargo’s CH-47F and PMKiowa Warrior OH-58, the reusable automated testing capability can be applied to all avionics capabilities including communications, navigational, sensors, actuators, etc. Introduction The Army’s Assistant Secretary of the Army (Acquisition, Logistics, and Technology) is spearheading efforts [2] for “rapid equipping,” “rapid fielding,” and transforming the Army’s acquisition processes. In response to this call, the Army’s Product Manager, Aviation Mission Equipment (PM–AME), is seeking to implement a process by which common software products, to include common avionics integration software, can be identified, acquired, tested, and integrated across the disparate Army Aviation platforms. Presented at the American Helicopter Society 66th Annual Forum, Phoenix, AZ, May 11-13, 2010. Copyright © 2010 by the American Helicopter Society International, Inc. All rights reserved. The PM-AME has identified the need for this process through the Common Software Initiative (CSI). Implementation of the CSI would position AME into conformance with the acquisition strategy outlined in Chapter 2 of the Defense Acquisition Guidebook [3] and with the directives of AR 70-1 Army Acquisition Policy [4]. These two DoD documents outline prescribed requirements for standardization, commonality, and systematic reusability that will guide Army Aviation practices for improving budget-to-capability performance. In support of CSI, PM-AME acquired a reusable Alt-Comms software product targeted for the PM-Cargo’s CH-47F and PM-Kiowa Warrior OH-58 platforms. This product controls the AN/ARC-201D and AN/ARC-231 radios and will be in service through 2020, until replaced by Joint Tactical Radio System (JTRS). PM-AME also contracted Tucson Embedded Systems (TES) to act as a third-party platform integrator testing the reusable product prior to it being released to these Platforms. TES has developed a cost-effective risk-reduced automated test environment to support the development and integration of reusable aviation software (see Figure 1). Figure 1. Integrator’s Environment Using a combination of actual target hardware (control display units, and military radios) and automated testing capabilities, an engineer can read in a software release and execute a set of test scripts to verify the control and functional operations of these Alt-Comm radio capabilities. There are 170 functions operating: Ground, HaveQuick, Maritime, SATCOM, SINCGARS, UHF LOS, and VHF ATC, and VHF FM capabilities. The test results were used in the development phase, quickly identifying operational issues to the software developer earlier in the life-cycle. TES worked closely with the developer improving the capabilities with each release and ensuring the product (software and integrator’s documentation) is prepared for Platform integration efforts. TES also worked with Army representatives from the Aviation & Mission Research, Development, and Engineering Center (AMRDEC) Aviation Engineering Directorate (AED) and the Software Engineering Directorate (SED) to confirm that the results were suitable as supporting artifacts for Airworthiness Qualification Substantiation Records as defined in AR 70-62 [5]. What AME and TES jointly discovered was a potential for a tremendous time and cost savings for the Army, which also, through reuse, represented a tremendous risk reduction to the program. TES modeled the process described in FAA Advisory Circular AC 20-148 [1] (see Figure 2) as it would be applied to the SED-AED certification process of the Army’s rotary fleet, assuming that software tests and testing artifacts could be reused across multiple platforms and support Reusable Software Component (RSC) testing as well as platform integration testing. The process, aligned with FAA’s AC 20-148, implies thirdparty developers could produce airworthy Reusable Software Components (RSC) and software Reusable Software Verification Components (RVC) which meet DO178B guidelines [6], build and execute system-level tests at a government-owned Aviation Systems Integration Facility (ASIF), and then with a high-level of confidence rebuild the RSC and RVC on platform-specific SILs and re-run the RVC saving both time and money. On completion, the components then proceed to flight-testing. Figure 2. Vision for Reusable Automated SIL Testing Through the process, an airworthiness qualification is achieved and an acceptance letter of the RSC and its reusable artifacts are presented back to the Developer. The RSC, RVC, and supporting documentation are subsequently reused for integration on other platform SILs, etc. AED and SED identified that the automation can be used in system-level testing in flight representative Platform System Integration Laboratories (SILs). The key was to have TES engineers work with the Platforms and define the insertion points for this automation, such that it did not “contaminate” ER el -3