Mission systems provide crucial elements of our warfighting capabilities--in the case of aviation mission systems, components integrat-ed directly onto an air vehicle and encompassing traditional avionics (communications, navigations and displays, for example) as well as specific warfighting capabilities (weapons and sensors).Current methods of acquiring these systems, however, lead to duplication of effort and a multiplicity of requirements for different contractors providing essentially the same capability. The Aviation Development Directorate (ADD) of the U.S. Army Aviation and Missile Research, Development and Engineering Command (AMRDEC) is researching new methods of acquiring aviation mission systems through a government-led architecture specification. This specification will describe the desired system characteristics, or "-ilities," such as reusability, portability and interoperability, and document enforceable requirements for these characteristics. This approach will foster competition and reuse across systems, and reduce timelines for managing obsolescence and acquiring new capa-bilities. A NEW APPROACH NEEDED Military services develop aviation mission systems from a program-centric perspective. In other words, each program is singularly responsible for satisfying its system performance requirements. This approach makes sense from the program manager's perspective, as they are able to manage cost, schedule and performance. The disadvantage, however, is that contractor-unique solutions are likely to preclude any component reuse across programs.Often, the Army acquires the same basic capability multiple times through independent procurements, each with unique sets of re-quirements implemented by different contractors. Additionally, any modifications or modernization almost certainly will have to come from the initial contractor, impeding a program's long-term supportability by limiting competition.Throughout the life cycle of a system, many common functions need upgrading, with repeated development, integration, testing and qualification. Using a program-centric approach may reduce initial development cost and schedule, but it sacrifices long-term afford-ability and supportability by making it impossible to share the upgraded capabilities across programs. Additionally, nonfunctional requirements such as openness, interoperability, upgradability and maintainability become secondary to system performance re-quirements and are often compromised in favor of near-term program performance.Overall, this program-centric perspective results in a loss of competition and innovation and increases long-term costs.DOD acquisition processes focus on what performance is required and not how it should be implemented, providing limited insight and understanding of the reasons behind the "how." When the government procures a capability this way, it inherits the business objectives of the contractor, which may not align with those of the government. The organization's business and technical goals influ-ence the architecture of that system, substantially affecting its life cycle. The government needs a systematic method to convey a sys-tem's characteristics accurately from a broader, enterprise perspective. This method would drive architecture decisions for the system and lay the groundwork for development and sustainment decisions.DOD has tried to tackle these challenges through an open systems architecture (OSA) approach that combines business and technical objectives that yield systems with severable modules that are subject to competition. But program-centric attempts and broad man-dates to implement an OSA have yet to adequately improve life cycle affordability, enable competition or shorten fielding timelines in the aviation community. This is because achieving and assessing many life cycle characteristics such as openness are subjective and are pursued without coordination between the program offices and other stakeholders. To achieve the potential benefits of an OSA, the Army needs to apply a comprehensive, systematic approach across the aviation enterprise.SHIFTING PERSPECTIVES ADD is investigating an approach to prioritize the government's business and technical objectives as part of the Joint Multi-Role Technology Demonstrator (JMR-TD), a science and technology program to demonstrate transformational vertical lift capabilities to prepare DOD for decisions regarding the replacement of the current vertical lift fleet. The JMR Comprehensive Architecture Strate-gy (JCAS) supports efficient development and sustainment of open and interoperable aviation mission systems.The JCAS is based on analyzing, documenting and tracing the government's business and technical goals, including key business driv-ers (for example, affordability, time to field, tactical overmatch, etc.), policy and processes. This analysis and documentation result in enforceable architecture requirements for aviation mission systems.The JCAS provides a layered architectural management approach to inform and constrain subsequent development activities. It also provides enforceable, traceable requirements for future procurements to conform to explicitly stated standards, processes or practices. It specifies a measure or verification method to prove desired characteristics or attributes. By providing traceability of the desired attributes and the means for achieving them, the strategy will lead to systems that are designed and implemented in a spe-cific, consistent manner to achieve enterprise goals.The JCAS proposes three levels of architectural management: reference architecture, objective architecture and system architecture. Throughout these levels, methods exist to enable identified improvements or changes as the JCAS matures.The reference architecture, the highest level of architecture in the JCAS, is intended to guide and constrain the development of sub-sequent levels of architectures. The reference architecture represents strategic-level interests by combining stakeholder concerns reflecting both business and technical perspectives. Its requirements are independent of a specific solution but still support desired stakeholder objectives, such as affordability and interoperability, in a common, consistent manner.A reference architecture provides common language and terminology, guides the application of technology, supports traceability of requirements to validate future architectures and provides a method to adhere to common standards and patterns. It facilitates the development of cross-platform capabilities by constraining the ability to develop unique architectural approaches. Options within the reference architecture apply to all programs within the organization's influence and include elements such as purpose, principles and standards.The objective architecture derives from the reference architecture and represents a way to identify opportunities for commonality across related programs, such as in a family of systems. Whereas the reference architecture is an overarching set of options, the ob-jective architecture represents the selections that meet the desired technical and business decisions for the family of systems. The objective architecture documents the tailoring and refinement by an organization to meet the missions of the related programs, as well as documentation of the methods to meet the requirements defined in the reference architecture.At the lowest level of architectural specification is the system architecture, which the procuring organization develops by further re-fining and tailoring the objective architecture to satisfy the performance requirements of a specific system. The system architecture further guides and constrains the architectural principles and methods that the system developers may use while still adhering to the higher-level organizational objectives. Because the system architecture is focused on architectural principles, it does not prescribe the system design and implementation decisions, leaving flexibility for many potential designs.CONCLUSION The JMR-TD is pursuing a series of demonstrations to mature various concepts of open systems. The final event, the capstone demonstration, begins with anticipated awards in June 2018 and runs through the end of 2020. It will help mature and validate the JCAS concept by determining if multiple related programs can use the same systematic approach to architecture to achieve desired characteristics. In the long term, the requirements to achieve these characteristics, which may provide the basis for a new generation of mission systems, will be encapsulated in a best-of-breed specification that leverages the observations and learning gained through the JMR demonstrations.To achieve the desired life cycle characteristics for air vehicles, the government must take a leading role in describing and specifying the architecture of its aviation mission systems. Ultimately, the JCAS is intended to be a basis for future procurements of aviation mission system capabilities, reducing the likelihood that individual programs will develop unique and difficult-to-support solutions. Such an approach will be needed to achieve and maintain capability overmatch in a rapidly changing world with ever-evolving threats.For more information, email usarmy.redstone.rdecom-amrdec.mbx.amrdec-add@mail.mil with the subject line "AL&T Article: Strength in Architecture."This article is published in the January -- March 2018 Army AL&T magazine.