ABSTRACT
Systems provide value through their ability to fulfill stakeholders’ needs. These needs evolve and often diverge from an original system's capabilities. Thus, a system's value to its ...stakeholders diminishes over time. Consequently, systems have to be periodically upgraded or replaced. Since replacement costs are often prohibitive, system adaptability is valuable. Adaptability entails the ability to modify an existing system or design of a system's architecture, such as changing, adding, removing, or replacing relevant elements as well as adjusting their reciprocal interactions.
In 2008, Engel and Browning proposed a Design for Adaptability concept based on Architecture Option (AO) theory. AO fuses Financial Options and Transaction Cost theories, seeking to design systems for optimal lifetime value. They asserted that designers should balance the benefits of adaptability against its affordability. More modularity is not always better; the amount of modularity alone is an insufficient and even misleading cause of value.
This follow‐up paper reports on a project, aimed at enhancing the AO theory and validating its applicability within diverse industrial environments. Through interactions with practicing system developers, the AO model was simplified and a modified Black–Scholes model was adapted into the engineering domain and successfully practiced. Six case studies were conducted within: food packaging, machine tools, automotive, aerospace, communication, and optoelectronics industries. All six industrial participants estimated, among other improvements, over 15% benefits in (1) reducing systems’ lifetime cost, (2) reducing systems’ upgrade cycle‐time, and (3) increased systems’ lifespan. These results demonstrate the industrial applicability and validity of the AO theory.
ABSTRACT
Developing products that are more easily adaptable to future requirements can increase their overall value. Product adaptability is largely determined by choices about product architecture, ...especially modularity. Because it is possible to be too modular and/or inappropriately modular, deciding how and where to be modular in a cost‐effective way is an important managerial decision. In this article, we gather data from four case studies to model effects of firms’ product architecture decisions at the component level. We optimize an architecture adaptability value (AAV) measure that accounts for both the benefits of more architecture options and the costs of interfaces. The optimal architecture prompted each firm to rearchitect an existing product to increase its expected future profitability. Several insights emerged from the case evidence during this research. (i) Although decomposing an architecture into an increasing number of modules increases product adaptability, the amount of modularity is an insufficient predictor of the adaptability value of a system. AAV, which also accounts for interface costs, provides an improved measure of appropriate modularity. (ii) Managers can influence the path of architectural evolution in the direction of increased value. This influence may diminish but does not disappear as products become more mature. Also, modularity and innovations coevolved, as the new modularizations suggested by AAV optimization prompted and guided searches for further innovations. (iii) When presented with the concepts of options, interface costs, and AAV, the firms’ designers and managers were initially skeptical. However, in each case, the modelers were able to rearchitect an actual product not only with increased AAV by our model (theoretical improvement) but also with actual future benefits for their firm. Postproject reports from each firm confirmed that the AAV modeling and optimization approaches were indeed helpful, equipping them to increase the adaptability, cost‐efficiency, lifespan, and overall value of actual products. The evidence suggests that firms can benefit from designing products for adaptability, but that how they do so matters. This study expands our understanding of modularity and adaptability by illuminating managerial decisions and insights about appropriate approaches to each.
The purpose of this paper is to broaden the practical notion of Taguchi's Quality Loss Function (QLF) from a static, one‐stage concept into a dynamic time‐varying tool. Taguchi challenged the old‐age ...notion of engineering tolerance and proposed a quadratic QLF that quantifies loss to society, caused by deviation of products and systems from their target values. Accordingly, design engineers attempt to set each technical parameter to minimize such systems' losses. Traditionally, failure mechanisms are assumed to affect systems' performance stochastically under a steady state. So often, technical parameters are set at the mid‐point between the lower and upper specification limits where they are least likely to cause a system failure. However, in reality, many failure mechanisms affect systems over time in a predictable and directional manner rather than stochastically. Such mechanisms are designated as “Directional Degrading Failure Mechanisms”. The paper describes an optimized robust design method based on setting the operating points of technical parameters to explicitly counteract the effects of such failure mechanisms. Then, the paper describes how to minimize the lifetime societal loss of a given system utilizing a cardiac pacemaker system. The consequence of this approach suggests an extension to the Taguchi's QLF from its current static confines to a dynamic, time‐varying concept achieving, in our example, ≈65% reduction in lifetime societal losses.
The overall lifecycle cost associated with product failures exceeds 10% of yearly corporations’ turnover. A major factor contributing to this loss is ineffective performance of software and systems ...Verification, Validation and Testing (VVT). Given these realities, we proposed a set of quantitative probabilistic models for estimating costs and risks stemming from carrying out any given VVT strategy Engel, A., Barad, M., 2003. A methodology for modeling VVT risks and costs. Systems Engineering Journal 6 (3), 135–151, Wiley InterScience, Online ISSN: 1520-6858, Print ISSN: 1098-1241. We also demonstrated that quality costs in software-intensive projects are likely to consume as much as 60% of the development budget. Finally, we showed that project cost and duration could be reduced by optimizing the VVT strategy, yielding about 10–15% reduction in development costs and project schedule Engel, A., Shachar, S., 2006. Measuring and optimizing systems’ quality costs and project duration. Systems Engineering Journal 9 (3), 259–280.
A key problem associated with such cost and time estimates is that input data are imprecise by nature. Certain parameters are better captured using tuple structures (e.g. Minimum, Most-likely and Maximum values). Other parameters can be better encapsulated using linguistic terms such as “High” or “Low”. This paper extends the above research by modeling the problem using the fuzzy logic paradigm. We estimate the quality cost occurring during the development of software for an avionic suite in a fighter aircraft and demonstrate that applying fuzzy logic methodology yields results comparable to estimations based on models using the probabilistic paradigm (less than 4% differences in each of the five VVT cost categories).
Systems Engineering discipline oversees the system's conceptual, logical, and physical integration. A collaborative mindset is a key success factor for complex systems' conceptual, logical, and ...physical integration. Currently, hybrid design methodologies across the enterprise (particularly ad-hoc collaborations such as cross-industry programs, public-private partnerships, corporate mergers, and everyday projects involving multiple disciplines) may result in islands or canyons of digitalization, automation, and model-driven design. Teams that rely mostly on informal or semiformal communication or exchange diagrams and documents may find it extremely hard to scale up and maintain the quality of multidisciplinary systems. We propose a method to decrease disparity and misalignment in Collaborative Multimodal Design projects, which relies on Category Theory - a mathematical theory of representations and transformations. Categorical Multimodal Design (CMD) defines a rigorous process for categorical concepts adoption and implementation in design activities and provides practical and easy-to-use tools to create integration schemes across multiple design disciplines. CMD thus lowers the entry barriers into formal paradigms for systems designers and engineers who may need to generate or process system-level concept representations but may not have the means to do so. We show how CMD can be applied in designing a passenger counting system with dual commercial and military aviation use cases.
