طراحی باز، ادغام موجودی و نگهداری ماژول ها

The adoption of open architecture has several economic implications in the life of an asset, including developmental, production, storage, training and maintenance costs. This research responds to an inquiry by the Program Executive Officer—Integrated Weapons System (US Department of the Navy) regarding the value of open architecture (OA) in the design of complex assets. With this intent, we evaluate how the inventory allocation of spare engines for the F-16 operations in the continental United States would be affected with and without the adoption of open architecture, focusing on the benefits of inventory pooling to meet the demand of many users from a small number of storage sites. We use a distance-constrained version of the Ardalan heuristic for solving the facility location problem, responding to practical limitations exposed by the model. This article shows that open architecture may provide substantial supply chain cost reduction, and simplification of the distribution network when combined with proper inventory storage policies.

The combined use of commonality and modularity in product design has allowed automobiles, aircraft, computers and a host of other machines (including most military systems) to be reusable beyond their first lifecycle and to be given many more years of operation. This versatility substantially impacts the availability and maintenance cost of many durable assets. Modularity enables the division of the product development effort among many specialists (firms or individuals), ensuring the development of the most advanced and competitive systems. Modularity facilitates the separation of component-wear phenomena as the system ages, enabling maintenance professionals to locate and repair damaged modules without affecting the integrity of other modules in the system. Commonality, however, presents a disadvantage that many engineers will recognize: the adoption of common design in a competitive environment hinders creativity and innovation in product development; suppliers of high-technology products would prefer to develop their own designs than to share them with competitors. The design team would rather showcase its capabilities, especially in the development of advanced systems or in the adoption of new technologies. Hence, while modularity remains a powerful product-development philosophy that brings agility and cost reduction to product design, the adoption of common designs for complex products may be not the best approach to system acquisition—especially in circumstances requiring the development of advanced technologies. In these scenarios, the traditional “commonality” must be enhanced with the adoption of “open architecture” features—allowing modules from competing sources to be used in the same system, without constraining the creativity and innovation from the designers involved in the development of the module. Open architecture provides the opportunity to introduce product aggregation, one of the three aggregation (or pooling) approaches to managing and improving supply-chain performance, along with time aggregation and place aggregation. Product aggregation is intended to reduce product variety without compromising the functionality required by the user. The purpose of this case study is to evaluate open architecture as the design philosophy for the acquisition of complex systems with advanced technologies. This is done by analyzing the case of the F-16 spare engines, showcasing the cost benefits that the US Air Force might be enjoying today had the aircraft engine suppliers been required to adopt open architecture. This study assumes that a complex system (such as the Joint Strike Fighter, or other weapon systems acquired by the uniformed services of the US Department of Defense) is a combination of hardware and software components that may be acquired from multiple developers or suppliers. This study proposes that the adoption of open architecture in the acquisition of these systems can substantially reduce the costs of these programs. Next section describes the problem that motivated this study, and Section 3 explains how open architecture affects product development and life-cycle management. Section 4 describes current inventory management policy and allocation of F-16 spare engines at Air Force bases in the contiguous United States. Section 5 introduces a brief literature review of the methodology used to rationalize F-16 spare engine allocation. Section 6 analyzes the case under three scenarios: the benchmark scenario, which is based on current policy, a scenario with limited inventory pooling, and a third scenario with open architecture of engine design. Section 7 presents the conclusions and suggestions for future research.

An important concern in supply-chain management is the identification of aggregation opportunities that exist in the design, storage and distribution of goods to the final customer. This aggregation, or pooling, can take place in three dimensions: time aggregation, place aggregation and product aggregation. The manager should evaluate the trade-offs in each of these aggregation opportunities in order to implement the correct product design, storage and distribution procedures. Time aggregation implies that the inventory is kept to meet the demand over longer or shorter periods of time. Place aggregation implies that the inventory is designed to meet the demand over one or many markets. Finally, product aggregation implies that a product or component is designed to meet the demand associated with one or more applications. When any or all of these aggregations are viable, the company enjoys substantial operational savings due to the reduction of safety stock; in addition, much of the coordination effort may be reduced. This paper analyzes the case of the F-16 spare engine storage to illustrate two types of pooling benefits: by place and by product. Here, product aggregation is achieved with the adoption of open architecture in product design. Place aggregation is achieved with judicious use of the classic Ardalan (1988) heuristics subject to a distance constraint, necessary to ensure the desired performance level. We draw several important lessons from this study: Open architecture is an effective means of product aggregation to facilitate supply-chain improvement for valuable complex assets. Open architecture can be leveraged by place aggregation when the asset is used by several facilities geographically distributed. Open architecture provides the greatest inventory reduction benefit when storage can be centralized. If centralization is not desirable, it can still provide substantial benefits, by judicious identification of a regional cluster of users to share joint inventory. Reduction in the number of storage points generally increases transportation cost. Hence, it is important to evaluate the trade-off between simplified infrastructure and reduced investment in inventories against increases in transportation cost. The purpose of this study is to evaluate the economic impact of adopting open architecture in the design of complex assets to reduce the lifecycle cost of maintaining those assets. The adoption of open architecture affects several economic components in the life of the asset, including developmental costs, maintenance costs, and inventory-management costs. This article focuses on the benefits of pooling the inventory necessary to meet the demand of many users into a small number of storage sites with product variety reduction obtained with open architecture. The example showcased in this analysis—distribution of spare engines for the F-16 in continental United States—amply supports open architecture as the design approach to reduce supply chain expenditures without compromising the availability of valuable assets. The relevance here is far beyond the potential savings that the F-16 program could have enjoyed, but is a lesson for future government programs—whether they are weapon systems or other assets supplied by two or more qualified suppliers. Several examples come to mind, among them unmanned aerial vehicles, the space program and high-speed rail equipment. More than 40 years since Hakimi (1965) first formulated the p-median problem, it is still necessary to warn managers in government of the importance to use rigorous techniques to make facility location decisions. Fok (2001) raised this issue, at the same time that he recommended the use of accessible techniques, such as the center of gravity method – for centralized storage – or the Ardalan heuristics – for multi-facility storage, as is our case. Future studies about the impact of open architecture on complex systems should expand the analysis to incorporate benefits provided by simplified maintenance, as well as to investigate the additional cost and time required to coordinate the developmental efforts to ensure a common interface. On the distribution side, the regular adoption of transshipment (lateral shipment) or the use of multiple storage units should be studied as alternatives to improve inventory pooling, and thus to enhance the value of open architecture in future product development programs.