Hybrid Genetic Bees Algorithm applied to Single Machine Scheduling with Earliness and Tardiness Penalties

This paper presents a hybrid Genetic-Bees Algorithm based optimised solution for the single machine scheduling problem. The enhancement of the Bees Algorithm (BA) is conducted using the Genetic Algorithm's (GA's) operators during the global search stage. The proposed enhancement aims to increase the global search capability of the BA gradually with new additions. Although the BA has very successful implementations on various type of optimisation problems, it has found that the algorithm suffers from weak global search ability which increases the computational complexities on NP-hard type optimisation problems e.g. combinatorial/permutational type optimisation problems. This weakness occurs due to using a simple global random search operation during the search process. To reinforce the global search process in the BA, the proposed enhancement is utilised to increase exploration capability by expanding the number of fittest solutions through the genetical variations of promising solutions. The hybridisation process is realised by including two strategies into the basic BA, named as â\u80\u9creinforced global searchâ\u80\u9d and â\u80\u9cjumping functionâ\u80\u9d strategies. The reinforced global search strategy is the first stage of the hybridisation process and contains the mutation operator of the GA. The second strategy, jumping function strategy, consists of four GA operators as single point crossover, multipoint crossover, mutation and randomisation. To demonstrate the strength of the proposed solution, several experiments were carried out on 280 well-known single machine benchmark instances, and the results are presented by comparing to other well-known heuristic algorithms. According to the experiments, the proposed enhancements provides better capability to basic BA to jump from local minima, and GBA performed better compared to BA in terms of convergence and the quality of results. The convergence time reduced about 60% with about 30% better results for highly constrained jobs

Designing collaborative roles and responsibilities in supply chain

Different tasks in the supply chains should be accomplished by well-defined collaboration of the members and functional sections in the organisations. Therefore, optimising the definition of roles and responsibilities for several supply chain processes is critical. Defining roles and responsibilities in the supply chain could be considered as a part of a broader concept called enterprise architecture. Supply Chain Operations Reference (SCOR) model can be used for constructing supply chain-focused enterprise architecture. Relations between different levels of organisation are important in enterprise architecture. Roles and responsibilities are the essential concepts for relating organisations, processes, people and systems that must perform certain processes. Although the SCOR model gives very helpful standardisation and its best practices, it does not give any suggestion about the proper design of organisational roles involved in each process. This paper proposes a framework for accurate definition of roles and responsibilities based on SCOR model. This concept can be extended for other types of collaborative organisations

Designing collaborative roles and responsibilities in supply chain

Different tasks in the supply chains should be accomplished by well-defined collaboration of the members and functional sections in the organisations. Therefore, optimising the definition of roles and responsibilities for several supply chain processes is critical. Defining roles and responsibilities in the supply chain could be considered as a part of a broader concept called enterprise architecture. Supply Chain Operations Reference (SCOR) model can be used for constructing supply chain-focused enterprise architecture. Relations between different levels of organisation are important in enterprise architecture. Roles and responsibilities are the essential concepts for relating organisations, processes, people and systems that must perform certain processes. Although the SCOR model gives very helpful standardisation and its best practices, it does not give any suggestion about the proper design of organisational roles involved in each process. This paper proposes a framework for accurate definition of roles and responsibilities based on SCOR model. This concept can be extended for other types of collaborative organisations

An improvement in calculation method for apparel assembly line balancing

259-264A calculation method has been developed to determine the number of workstations and cycle time, considering one machine type at each workstation, normally preferred in apparel industries. The findings are compared with the earlier findings with respect to criterions such as the number of workers, the level of workers' skill, the number of used machine and the number of worker's movement between machines. The results show improvement in line balancing when taking into consideration the machine type feature. Hence, a model is proposed for apparel assembly line balancing to take into consideration the machine type assigned to each workstation so that it has a specific advantage for apparel assembly lines

A modified imperialist competitive algorithm for a two-agent single-machine scheduling under periodic maintenance consideration

Scheduling with periodic maintenance has been widely studied. However, multi-agent scheduling with simultaneous considerations of periodic maintenance has hardly been considered until now. In view of this, this research focuses on the problem of scheduling jobs that come from two agents on a single machine under periodic maintenance constraint with the objective of minimising the total completion time of the jobs of the first agent while keeping the maximum tardiness of other agent below or at a fixed level UB. We present some new dominance properties for this strongly NP-hard problem. And next, using these properties, we develop a novel imperialist competitive algorithm for the problem. Various parameters of the proposed algorithm are reviewed by means of Taguchi experimental design. For the evaluation of the proposed ICA, problem data was generated to compare it against a genetic algorithm. The results of computational experiments show the good performance of the proposed algorithm

Flexibility in service parts supply chain: a study on emergency resupply in aviation MRO

Recent trends in the commercial aviation industry have resulted in rapidly increasing complexity and decentralisation in service parts logistics systems. As a consequence, MRO service providers tend to adopt more flexible strategies, such as service parts sourcing and demand fulfilment for customers with different service-level requirements. The MRO service providers often enter into cooperative agreements with other service providers to pool inventories, enabling them to increase their flexibility in delivering services to multiple airlines with different contractual terms. Although using cooperative strategies, such as emergency resupply, is useful to increase flexibility, the inherent complexity of optimal mechanism is a critical issue that needs to be further investigated. To this aim, we consider a repairable service parts inventory system with multi-customer classes and develop an optimal emergency resupply policy. Following this, to overcome the intractability issue of finding the optimal policy, an efficient approximation method is proposed. Numerical results indicate that the proposed approximation method is highly accurate, and leads to a significant costs reduction. This paper sheds light on the effectiveness of emergency resupply policy that improves MRO service providers' flexibility and enables them to ensure responsive service parts inventory