Yuchun Xu

Development of a fuel consumption optimization model for the capacitated vehicle routing problem

Fuel consumption accounts for a large and increasing part of transportation costs. In this paper, the Fuel Consumption Rate (FCR), a factor considered as a load dependant function, is added to the classical capacitated vehicle routing problem (CVRP) to extend traditional studies on CVRP with the objective of minimizing fuel consumption. We present a mathematical optimization model to formally characterize the FCR considered CVRP (FCVRP) as well as a string based version for calculation. A simulated annealing algorithm with a hybrid exchange rule is developed to solve FCVRP and shows good performance on both the traditional CVRP and the FCVRP in substantial computation experiments. The results of the experiments show that the FCVRP model can reduce fuel consumption by 5% on average compared to the CVRP model. Factors causing the variation in fuel consumption are also identified and discussed in this study.

A framework for design knowledge management and reuse for Product-Service Systems in construction machinery industry

In the global market, heavy construction machinery manufacturers are transforming their business from selling products to providing services based on their products, i.e. transforming to Product-Service Systems (PSS) business model. This business transformation requires manufacturers to learn past design experience not only on the product design, but also on the product usage and maintenance. Effective knowledge and information management systems can help the business to obtain and reuse the past knowledge in new product design. This study aims to develop an integrated knowledge management and reuse framework for Product-Service Systems business in construction machinery industry. The prototype of such a knowledge management and reuse system has been developed and initially validated. The research shows that the developed knowledge management and reuse system can effectively help Product-Service Systems design for construction machinery.

Cost Engineering for manufacturing: Current and future research

The article aims to identify the scientific challenges and point out future research directions on Cost Engineering. The research areas covered in this article include Design Cost; Manufacturing Cost; Operating Cost; Life Cycle Cost; Risk and Uncertainty management and Affordability Engineering. Collected information at the Academic Forum on Cost Engineering held at Cranfield University in 2008 and further literature review findings are presented. The forum set the scope of the Cost Engineering research, a brainstorming was held on the forum and literatures were further reviewed to understand the current and future practices in cost engineering. The main benefits of the article include coverage of the current research on cost engineering from different perspectives and the future research areas on Cost Engineering.

Integrating through-life engineering service knowledge with product design and manufacture

Even though knowledge management has been a subject of research for a long time, management of through-life engineering service knowledge (SK) has started getting more attention quite recently. With the help of literature review and analysis, this paper identifies possible drivers to extend the product life cycle, presents definitions of ‘knowledge’ and ‘engineering service knowledge’ and identifies research gaps and challenges in digital feedback of through-life engineering SK to product design and manufacture. The paper presents a causal loop model to represent causes and effects of through-life engineering SK on product design and manufacture. A digital framework is presented to address integration challenges in digital feedback of through-life engineering SK to product design and manufacture. The digital framework is developed with the intention of developing a SK backbone demonstrator application. Industrial experts have validated the initial framework. Detailed case studies shall be undertaken to enhance this framework in future.

Energy-aware integrated process planning and scheduling for job shops:

Process planning that is based on environmental consciousness and energy-efficient scheduling currently plays a critical role in sustainable manufacturing processes. Despite their interrelationship, these two topics have often been considered to be independent of each other. It therefore would be beneficial to integrate process planning and scheduling for an integrated energy-efficient optimisation of product design and manufacturing in a sustainable manufacturing system. This article proposes an energy-aware mathematical model for job shops that integrates process planning and scheduling. First, a mixed integrated programming model with performance indicators such as energy consumption and scheduling makespan is established to describe a multi-objective optimisation problem. Because the problem is strongly non-deterministic polynomial-time hard (NP-hard), a modified genetic algorithm is adopted to explore the optimal solution (Pareto solution) between energy consumption and makespan. Finally, case studies of energy-aware integrated process planning and scheduling are performed, and the proposed algorithm is compared with other methods. The approach is shown to generate interesting results and can be used to improve the energy efficiency of sustainable manufacturing processes at the process planning and scheduling levels.

Process mining: from theory to practice

Purpose – The purpose of this paper is to present a comparison of a number of business process mining tools currently available in the UK market. An outline of the practice of business process mining is given, along with an analysis of the main techniques developed by academia and commercial entities. This paper also acts as a primer for the acceptance and further use of process mining in industry, suggesting future directions for this practice.Design/methodology/approach – Secondary research has been completed to establish the main commercial business process mining tool vendors for the market. A literature survey has also been undertaken into the latest theoretical techniques being developed in the field of business process mining.Findings – The authors have identified a number of existing commercially available business process mining tools and have listed their capabilities within a comparative analysis table. All commercially available business process mining tools included in this paper are capable ...

A variable neighborhood search with an effective local search for uncapacitated multilevel lot-sizing problems

In this study, we improved the variable neighborhood search (VNS) algorithm for solving uncapacitated multilevel lot-sizing (MLLS) problems. The improvement is twofold. First, we developed an effective local search method known as the Ancestors Depth-first Traversal Search (ADTS), which can be embedded in the VNS to significantly improve the solution quality. Second, we proposed a common and efficient approach for the rapid calculation of the cost change for the VNS and other generate-and-test algorithms. The new VNS algorithm was tested against 176 benchmark problems of different scales (small, medium, and large). The experimental results show that the new VNS algorithm outperforms all of the existing algorithms in the literature for solving uncapacitated MLLS problems because it was able to find all optimal solutions (100%) for 96 small-sized problems and new best-known solutions for 5 of 40 medium-sized problems and for 30 of 40 large-sized problems.

Towards lean transformation: the analysis of lean implementation frameworks

Purpose – Failure in engaging shop floor employees (including supervisory staff) in lean, lacking of supervisory skills in leading workers and lacking of lean technical knowhow among the shop floor employees are some of the major obstacles in lean transformation. One of the reasons of inefficient lean transformation is the shortages in frameworks or plans in implementing lean. The purpose of this paper is to investigate the shortfalls in the current lean implementation frameworks. Design/methodology/approach – The frameworks were analysed according to the following criteria: first, “What” is the approach of lean implementation, i.e. top-down or bottom-up; second, “How” to implement lean (description of steps or sequences of lean implementation along the lean journey); third, “Why” – the reason of adoption of the proposed lean tools, techniques or practices (thereafter TTPs) in each phase of lean implementation; and fourth, “Who” are the targeted internal stakeholders to use or apply the lean TTPs that wer...

A System for Measuring High-reflective Sculptured Surfaces Using Optical Noncontact Probe

Abstract With the development of industry more and more high-reflective sculptured surfaces are required to be measured quickly and accurately. For solving this problem a new optical probe with three incidence lights and a receptor has been developed. Two polarizing plates with mutually perpendicular polarizations are used to eliminate the disturbance of the specular light. A system based on 3-D coordinate measuring machine, PH10M motorized head and the new developed probe has been built. The system can track and measure the unknown free form sculptured surface automatically. Measures for improving accuracy and performance of the system are studied. The effectiveness of the proposed system has been tested by experiments.

A framework for ontology-based product design knowledge management

In order to enhance the reuse of product design knowledge, a design knowledge management framework is proposed, which consists of three functional parts: design knowledge acquisition, knowledge modeling, and design knowledge retrieval. A method for design knowledge modeling based on ontology is studied, which includes design knowledge ontology definition, design knowledge base building, and a multi-views strategy of design knowledge retrieval. A case study is conducted for mechanical product design knowledge management, and discussions about the ontology-based product design knowledge management are given.