Concurrent Engineering

A simple icon-based flowcharting methodology for capturing concurrency of tasks and activities during product design and development is described herein. Eight shape-icons, five flow-icons, and three line-icons are used to represent the various types of activities, information flow directions, and data connections, respectively. The methodology is quite general and can be used to capture various types of relationships in most life-cycle processes, such as concurrent workflow, or during an enterprise mapping. Precedent relationships, such as relative placements of tasks, and timing (such as start, end, or looping) of tasks can also be easily addressed. If we combine re-engineering objectives with such flowcharting methodology, one could also get answers to a broad range of process improvement questions, such as what activity to curtail; when to overlap, loop, or sequence a set of tasks; how to insure their effectiveness; and how to best position them on the process map, to improve the overall operational efficiency. Strategic use of such flowcharts for designing, evaluating alternatives, reducing time-to-market, and life-cycle costs can enable and lead an enterprise to be a lean organization.

While quality management systems are familiar to industries for continuous improvements of products, the associated tools can also make significant contributions to address environmental concerns, aligning eco-design in the product improvement process. In this context, this article focuses on the adaptions of quality tools for supporting the generation of eco-design concepts. Particularly, this article develops a method that integrates quality function deployment and functional analysis via relational matrices. The proposed method has three steps. In step 1, an existing design is analyzed, and the associations between design entities are captured in three types of relational matrices: requirements and metrics, metrics and components, and functions and components. In step 2, the mapping between requirements and functions are determined via matrix multiplications, and then a morphological chart is established to generate possible design concepts. In step 3, the generated concepts are evaluated using Pugh charts via the delegated engineering metrics. A hair dryer has been selected as an application to demonstrate the proposed method for supporting eco-design.

Aerospace is very important to the Canadian economy, with over 80,000 employees and generating over $20 billion dollars in revenue. However, this industry like many others is facing many challenges. One of them is the difficulty in being able to estimate design effort required in a design project, which impacts not only resource requirements and lead-time but also the final cost. This article presents the findings of a case study conducted for Pratt & Whitney Canada, recognized as a global leader in the design and manufacturing of aircraft engines. The study models parametric cost estimation relationships to estimate the design effort of integrated blade-rotor low-pressure compressor fans. Several effort drivers are selected to model the relationship. Comparative analyses of three types of models are conducted. The model with the best accuracy and significance in design estimation is retained.

Product architecture can influence different aspects of product lifecycle including manufacturing, assembly, and supply chain. The purpose of this article is to employ hierarchical cluster analysis for developing product architecture to support product variety. Design structure matrix is used to visualize and analyze product architecture in view of product modules, overlapping modules, and bus components. The proposed method for design structure matrix clustering consists of three phases. The first phase is component filtering to identify components that should be classified as bus components. The second phase is approximate structure formation that preliminarily organizes similar components to form a diagonal matrix. The third phase is partitioning analysis that finalizes the modules’ boundary to yield the structured matrix as the solution of design structure matrix clustering. To examine the solution’s quality, minimum description length from literature is used. Then, the proposed method is demonstrated via two literature examples and compared with the solutions by the manual and genetic algorithm approaches. One unique advantage of the proposed method is that the user can obtain and inspect the approximate structure in view of the diagonal matrix before finalizing the structured solution (e.g. estimate the number of modules).

This article presents a method for calculating cost savings of shared architectures in industrial companies called Architecture Mapping and Evaluation. The main contribution is an operational method to evaluate the cost potential and evaluate the number of product architectures in an industrial company. Experiences from the case company show it is possible to reduce the number of architectures with 60% which leads to significant reduction in direct material and labor costs. This can be achieved without compromising the market offerings of products. Experiences from the case study indicate cost reductions between 0.5% and 2% of turnover. The main implication is that the method provides a quantitative basis for the discussion on whether or not to implement shared product architectures. This means a more fact-based approach is introduced.

Industry-related competitiveness and reduction in manufacturing cost can be achieved by selection of ideal tolerance. Implementing non-traditional techniques for tolerance allocation to various parts in a mechanical assembly is an enervating procedure. Analytical methods are implemented to obtain creditable design. The main objective of this article is to minimize the manufacturing cost, quality loss, and T_RSS (root sum square tolerance) for complex mechanical assemblies. The proposed methodology deals with the reciprocal exponential function. Hence, it is used to solve the problem for obtaining the closed-form solution by Lagrange multiplier method which integrates Lambert W function. The illustrations used in the research article demonstrate the feasibility and effectiveness of the traditional approaches. The results obtained also show that tolerance can be allocated economically and precisely. Here, non-traditional optimization methods are correlated and finally their performances are analyzed.

Nowadays, as the manufacturing outsourcing activities are becoming increasingly explosive, cutting-tools are gradually being considered as a kind of strategical socialized manufacturing resource. Therefore, focusing on cutting-tools, this article proposes a novel cutting-tool service mode called industrial product service system for cutting-tools. Based on industrial product service system for cutting-tools, the methodology of cutting-tool delivery in the context of industrial product service system is further studied, which comprises two sub-models. First, a cutting-tool demand prediction model is established to obtain the types and quantities of cutting-tool demands in the next day from each industrial product service system for cutting-tool customer. Then, the second sub-model is a just-in-time cutting-tool delivery model, wherein, a modified economic order quantity model and genetic algorithm are applied to optimize the delivery time and routing constrained by the delivery time window. Finally, a comprehensive use case is studied to illustrate the feasibility and applicability of the proposed models.