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Parallel two-sided assembly lines are usually designed to produce large-sized products such as trucks and buses. In parallel two-sided assembly lines, both left and right sides of the line are used for manufacturing one or more products on two or more assembly lines located parallel to each other. The purpose of this paper is to develop a new mathematical model for the parallel two-sided assembly line balancing problem that helps to evaluate and validate the balancing operations of the machines such as removal of tools and fixtures and reallocating the operators.

The proposed approach is explained with the help of an example problem. In all, 22 test problems are formed using the benchmark problems P9, P12, P16 and P24. The results obtained are compared among approaches of the task(s) shared, tool(s) shared and both tool(s) and task(s) shared for effect on efficiency as the performance measure. The solution presented here follows the exact solution procedure that is solved by Lingo 16 solver.

Based on the experiments, line efficiency decreases when only tools are shared and increases when only tasks are shared. Results indicate that by sharing tasks and tools together, better line efficiency is obtained with less cost of tools and fixtures.

According to the industrial aspect, the result of the study can be beneficial for assembly of the products, where tools and tasks are shared between parallel workstations of two or more parallel lines.

According to the author’s best knowledge, this paper is the first to address the tools and tasks sharing between any pair of parallel workstations.

Presents some theoretical principles and empirical evidence relating to the new Swedish production systems for final assembly of motor vehicles. Contends that in these production systems it is possible simultaneously to enhance efficiency and quality of working life. Briefly sketches three production forms as they apply to the final assembly of automobiles and discusses the societal environments in which these different forms of production have evolved. Focuses on Volvo′s Swedish Uddevalla plant as one of the main examples so far of a reflective production system for final assembly of automobiles. Amplifies the analysis of different production flow patterns for final assembly and in particular addresses the issue of semi‐parallel mechanistic production flow and parallel organic production flow as alternatives to serial flow on a conventional line assembly.

This paper aims to review and discuss four aspects of mixed-model assembly line balancing (MMALB) problem mainly on the optimization angle. MMALB is a non-deterministic polynomial-time hard problem which requires an effective algorithm for solution. This problem has attracted a number of research fields: manufacturing, mathematics and computer science.

This paper review 59 published research works on MMALB from indexed journal. The review includes MMALB problem varieties, optimization algorithm, objective function and constraints in the problem.

Based on research trend, this topic is still growing with the highest publication number observed in 2016 and 2017. The review indicated that the future research direction should focus on human factors and sustainable issues in the problem modeling. As the assembly cost becomes crucial, resource utilization in the assembly line should also be considered. Apart from that, the growth of new optimization algorithms is predicted to influence the MMALB optimization, which currently relies on well-established algorithms.

The originality of this paper is on the research trend in MMALB. It provides the future direction for the researchers in this field.

In recent years, assembly lines have been reintroduced in the Swedish automotive industry and, in many cases, have replaced those so‐called alternative assembly systems which had their roots in the 1970s. This paper reviews and evaluates some explicit reasons given for the return to the assembly line. It also considers whether the decisions to replace alternative assembly systems with assembly lines may have been driven by other factors and mechanisms than those implicit in these arguments and, if so, what other factors could explain their reintroduction. There is also a discussion of which dimensions that should be taken into account when choosing between alternative assembly systems and assembly lines and empirical data are used to shed more light on the issues discussed in the article. The authors report one study that compares automobile assembly in an alternative assembly system with assembly of the same products after introducing an assembly line. They also briefly discuss reasons for and experiences from the recent introduction of alternative assembly systems in the Japanese electronics industry. In this case, so‐called cellular assembly systems have replaced assembly lines.

Discusses production models for final assembly in the automotive industry and also reports on the performance of one final assembly plant representing an innovative production model, namely the Volvo Uddevalla plant. Briefly considers some issues and pitfalls in current production model discourse, and in this connection introduces a distinction between two manufacturing models and broader industrial models. Describes two manufacturing models for final assembly work as namely the “serial flow model” and the “parallel flow model”. Discusses the Japanese “lean production”, sometimes synonymous with “Toyotism”, as an industrial model and the impact of socio‐economic and socio‐cultural contexts on manufacturing models and industrial models. Concludes that the Uddevalla plant highlights the paradox that long cycle time work in parallel flow assembly systems is in fact more efficient than short cycle time work in serial flow systems, provided that suitable technical and administrative preconditions exist. Therefore, the engineering point of view and the Swedish experiences of innovative manufacturing systems should be carefully considered in the current production model discourse.

The purpose of this paper is to develop the method of generating assembly sequences, which can be used in the shipbuilding industry. The method must take into account the assumptions specific for assembly processes of large-size steel ship hulls, among others, a large number of connections, multi-stage and parallel assembly, set priority relations between connections.

The assembly sequence is presented as a directed acyclic graph, whose vertices are mutually uniquely assigned to connections on a hull structure. The minimization of the number of unmet priority precedence of performing connections has been proposed as a criterion of optimization. The genetic algorithm has been proposed as a method to solve problems.

The proposed method allows to model the acyclic assembly process of welded structures and find solutions minimizing the objective function even for very complex problems. Because of this, the method has a chance to be used in shipbuilding.

Mathematical formulation of priority assumptions is quite laborious. The possibility of partial automation of this process should be considered. Due to the complexity of the problem, a relatively simplified objective function has been proposed. In assembling a hull, additional criteria should be taken into account. It is the direction of further research.

The method can be successfully used in shipbuilding and in planning the production of other steel welded structures, among others, tanks, components of bridges, offshore structures. Examples of calculations were performed on an actual structure of a hull fragment.

A new way of coding the acyclic serial-parallel sequence was designed. The proposed method allows to analyse the sequence using the graph theory. Original, two-part crossover and mutation operators for assembling sequence were proposed.

Additive manufacturing (AM) offers substantial flexibility in shape, but much less flexibility in materials and functionality – particularly at small size scales. A system for automatically incorporating microscale components would enable the fabrication of objects with more functionality. The purpose of this paper is to consider the potential of self‐assembly to serve as an automated programmable integration method. In particular, it addresses the ability of random self‐assembly processes to successfully assemble objects with high performance despite the possibility of assembly errors.

A self‐assembled thermoelectric system is taken as a sample system. The performance expectations for these systems are then predicted using modified one‐dimensional models that incorporate the effects of random errors. Monte‐Carlo simulation is used to predict the likely performance of self‐assembled thermoelectric systems and evaluate the impact of key process and system design parameters.

While assembly yield can drop quickly with increasing numbers of assembled parts, large functional assemblies can be constructed by arranging components in parallel to provide redundancy. In some cases, the performance losses are minimal. Alternatively, sensing can be incorporated to identify perfect assemblies. For small assemblies, the probability of perfection may be high enough to achieve an acceptable assembly rate. Small assemblies could then be combined into larger functional systems.

The paper identifies two strategies that can guide the development of AM processes that incorporate miniature components to increase the system functionality. The analysis shows that this may be possible despite significant errors in the self‐assembly process because systems may be tolerant of significant assembly errors.

Argues that the design of the Volvo Uddevalla plant may be described as a process with an “internal logic” in which design options were eliminated through irreversible design decisions until only one alternative remained ‐ an unorthodox alternative comprising, for example, long cycle time work never used before for full‐scale production of automobiles. Contends that the most innovative features of the Uddevalla plant ‐ i.e. the detailed layout in the assembly workshops and the corresponding unorthodox production principles used ‐ were in many respects an unanticipated outcome of the design process. Pre‐existing gross layout of the plant as well as the interaction between the materials feeding techniques adopted and the operation of the automated guided vehicle system. When this was perceived by the Volvo managers, the design process had passed the point of no return, i.e. the investments made and lack of time prevented regression to more traditional layouts and production principles.

This paper aims to address a distributed assembly permutation flow-shop scheduling problem (DAPFSP) considering budget constraints and factory eligibility. The first stage of the considered production system is composed of several non-identical factories with different technology levels and so the factories' performance is different in terms of processing time and cost. The second stage is an assembly stage wherein there are some parallel work stations to assemble the ready parts into the products. The objective function is to minimize the maximum completion time of products (makespan).

First, the problem is formulated as mixed-integer linear programing (MIP) model. In view of the nondeterministic polynomial (NP)-hard nature, three approximate algorithms are adopted based on variable neighborhood search (VNS) and the Johnsons' rule to solve the problem on the practical scales. The proposed algorithms are applied to solve some test instances in different sizes.

Comparison result to mathematical model validates the performance accuracy and efficiency of three proposed methods. In addition, the result demonstrated that the proposed two-level self-adaptive variable neighborhood search (TLSAVNS) algorithm outperforms the other two proposed methods. Moreover, the proposed model highlighted the effects of budget constraints and factory eligibility on the makespan. Supplementary analysis was presented by adjusting different amounts of the budget for controlling the makespan and total expected costs. The proposed solution approach can provide proper alternatives for managers to make a trade-off in different various situations.

The problem of distributed assembly permutation flow-shop scheduling is traditionally studied considering identical factories. However, processing factories as an important element in the supply chain use different technology levels in the real world. The current paper is the first study that investigates that problem under non-identical factories condition. In addition, the impact of different technology levels is investigated in terms of operational costs, quality levels and processing times.

The purpose of this paper is to develop and test a design approach based on the investigation of the sensitivity of assembly systems to volume fluctuations as part of the selection process of alternative design solutions for scalable assembly systems on the basis of a real industrial case study.

A conceptual approach for the (re‐)design of a scalable assembly system is developed on the basis of an industrial case research using axiomatic design (AD) for the top level structuring of the framework incorporating useful methods and insights obtained from a thorough literature review and from previous research work.

The findings of this research are limited due to the focused nature of a case study based research. However, the obtained results encourage assuming its transferability to similar problems.

Significant research has been done in the design of assembly systems for high product variety, but the review of literature in this field still identifies many opportunities for future research. This paper responds to the clearly identified research need of a methodological guidance regarding the design of scalable assembly systems and offers a practically proven help to improve the efficiency of the design process and the quality of the design results.