A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> Intelligent agent technology is a rapidly developing area of research. However, in reality, there is a truly heterogeneous body of work being carried out under the 'agent' banner. In this paper, software agent technology is introduced by briefly overviewing the various agent types currently under investigation by researchers. <s> BIB001 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> Abstract Effective and efficient implementation of intelligent and/or agile manufacturing systems requires an enterprise level integration. The first step in this direction is to integrate design, process planning and and scheduling. This paper describes a bidding-based approach to the integration of computer-aided design, process planning and real time scheduling. The product is represented in a STEP model with detailed design and administrative information including design specifications, batch size, and due dates. Upon arrival at the manufacturing facility, the product is registered in the shop floor manager which is essentially a coordinating agent. The shop floor manager broadcasts the product's requirements to the machines. The shop contains autonomous machines that have knowledge about their functionality, capabilities, tooling and schedules. Each machine has its own process planner and responds to the product's request in a way that is consistent with its capabilities and capacities. When more than one machine offers certain process(es) for the same requirements, they enter into negotiation. Based on processing time, due date and cost, one of the machines wins the contract. The successful machine updates its schedule and advises the product to request raw material for processing. The concept was implemented using a multi-agent system in an object-oriented programming language. The task decomposition and planning are achieved through contract nets. Examples are included to illustrate the approach. <s> BIB002 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> This paper describes a conceptual framework for applying a multi-agent system to process planning for integrating design, process planning and shop floor scheduling so that a distributed, cooperative and integrated process planning system is constructed. The problem in process planning has been mapped onto a multi-agent architecture based on multistage cooperation. The multi-agent system has some common characteristics, such as distribution, autonomy, interaction and openness, which are helpful for the traditional architecture to be transferred to the distributed, cooperative architecture for process planning system. An agent-based framework for an integrated, distributed and cooperative process planning system (IDCPPS) integrates all the activities of process planning into a distributed intelligent open environment. Agents in the agent-based framework for the IDCPPS can be organized dynamically and cooperate with each other to perform an appointed task flexibly. In addition, using CORBA technology, a prototype system of the IDCPPS is implemented. <s> BIB003 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> With the fast development of the world economy, distributed virtual manufacturing is becoming increasingly important since it can respond rapidly to market changes and make resource sharing more efficient among manufacturing partners. In this environment, partners may be located at different geographical locations, and co-operation among partners is a vital task and thus concurrent planning and scheduling has become a challenging research topic. This paper presents a computerized model that can integrate these manufacturing functions and resolve some of the critical problems in distributed virtual manufacturing, such as virtual co-operation, optimal partner selection, etc. This integration model is realized through a multi-agent approach that provides a practical approach for software integration in a distributed environment. A cost function is proposed and adopted for optimal partner selection in a virtual enterprise, which not only considers a partner's manufacturing capability and process requirements, but also the processing time, partner's location and product due date. Through establishing a virtual manufacturing model in a simulated environment, the proposal was validated with a case study. It shows that the proposed methodology can satisfy the distribution and agility requirements. This approach is able to contribute to the reduction of product cost, improving product quality and shortening lead time, compared to the sequential approach in the normal engineering and production practice. <s> BIB004 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> Intelligent software agents are a promising approach to improve information logistics in manufacturing enterprises. This paper deals with the application of agents in the area of process planning and production control. Thus, enterprises will be able to fulfil the requirement of flexible, reliable and fault-tolerant manufacturing. Fulfilment of these requirements is a prerequisite for successful participation in modern business alliances like supply chains and virtual enterprises. Thus, agent-based improvements of information logistics enable enterprises to face the challenges of competition successfully. Current research activities focus on the development of agent-based systems for integrated process planning and production control. They led to the IntaPS approach, which is presented in this paper. Furthermore, the integration of different agent-based systems in context of collaborative manufacturing in supply chains will be discussed. <s> BIB005 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> A changing shop floor environment characterized by larger variety of products in smaller batch sizes requires creating an intelligent and dynamic process planning system that is responsive and adaptive to the rapid adjustment of production capacity and functionality. In response to the requirement, this research proposes a new methodology of distributed process planning (DPP). The primary focus of this paper is on the architecture of the new process planning approach, using multi-agent negotiation and cooperation. The secondary focus is on the other supporting technologies such as machining feature-based planning and function block-based control. Different from traditional methods, the proposed approach uses two-level decision-making—supervisory planning and operation planning. The former focuses on product data analysis, machine selection, and machining sequence planning, while the latter considers the detailed working steps of the machining operations inside of each process plan and is accomplished by intelligent NC controllers. By the nature of decentralization, the DPP shows promise of improving system performance within the continually changing shop floor environment. <s> BIB006 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> Manufacturing process planning is the process of selecting and sequencing manufacturing processes such that they achieve one or more goals and satisfy a set of domain constraints. Manufacturing scheduling is the process of selecting a process plan and assigning manufacturing resources for specific time periods to the set of manufacturing processes in the plan. It is, in fact, an optimization process by which limited manufacturing resources are allocated over time among parallel and sequential activities. Manufacturing process planning and scheduling are usually considered to be two separate and distinct phases. Traditional optimization approaches to these problems do not consider the constraints of both domains simultaneously and result in suboptimal solutions. Without considering real-time machine workloads and shop floor dynamics, process plans may become suboptimal or even invalid at the time of execution. Therefore, there is a need for the integration of manufacturing process-planning and scheduling systems for generating more realistic and effective plans. After describing the complexity of the manufacturing process-planning and scheduling problems, this paper reviews the research literature on manufacturing process planning, scheduling as well as their integration, particularly on agent-based approaches to these difficult problems. Major issues in these research areas are discussed, and research opportunities and challenges are identified <s> BIB007 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> Process planning and scheduling are considered as two separate and distinct phases in manufacturing. Traditional approaches to these problems do not consider the constraints of both domains simultaneously and can only result in sub-optimal solutions. This separation becomes a barrier to further improving manufacturing performance. Most process planning and scheduling systems are off-line and centralized. The process plans generated off-line may become invalid at the time of plan execution. On the other hand, scheduling based on rigid process plans may have already lost the optimal options. Today, there is an increasing need for the integration of process planning and scheduling to generate more realistic and practical solutions. This paper provides a literature review on the integration of process planning and scheduling, particularly on agent-based approaches. It is followed by an overview of our approach toward distributed process planning and scheduling. The paper is finally concluded with future research opportunities. <s> BIB008 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> This paper presents a hybrid-based multi-agent system (MAS) for integrating process planning with scheduling/rescheduling in job shops or similar kinds of flexible manufacturing environments. The approach is called Online Hybrid Agent-based Negotiation (oHAN). It employs the affected operations rescheduling approach to reschedule the operations affected directly or indirectly by the disruptions. The proposed MAS architecture comprises local agents, which are the part and machine agents, and a supervisor agent. The local agents detect the production disturbances and reschedule the affected operations via decentralized negotiations. A comprehensive set of process plan flexibilities including flexible routings and alternative machines is considered during rescheduling. The supervisor agent coordinates and monitors the rescheduling process in order to ensure the observance of a global rescheduling objective. An online hybrid contract-net negotiation protocol (oHCNP) has been established to control the interac... <s> BIB009 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> Abstract This paper is on the development of an agent-based approach for the dynamic integration of the process planning and scheduling functions. In consideration of the alternative processes and alternative machines for the production of each part, the actual selection of the schedule and allocation of manufacturing resources is achieved through negotiation among the part and machine agents which represent the parts and manufacturing resources, respectively. The agents are to negotiate on a fictitious cost with the adoption of a currency function. Two MAS architectures are evaluated in this paper. One is a simple MAS architecture comprises part agents and machine agents only; the other one involves the addition of a supervisor agent to establish a hybrid-based MAS architecture. A hybrid contract net protocol is developed in the paper to support both types of MAS architectures. This new negotiation protocol enables multi-task many-to-many negotiations, it also incorporates global control into the decentralized negotiation. Simulation runs are conducted to compare the performance of the proposed MAS-based IPPS approaches and that of an evolutionary algorithm. It also shows that the hybrid-based MAS, with the introduction of supervisory control, is able to provide integrated process plan and job shop scheduling solutions with a better global performance. <s> BIB010 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> Agent technology has been considered as a promising approach for developing process planning systems and optimizing process plans in a distributed environment. A number of researchers have attempted to use agent technology in process planning for the purpose of integrating systems, tools and algorithms which are geographically distributed. In this paper, the historical background of agent technology is systematically reviewed. A comprehensive review of agent technology and its applications in manufacturing is presented including the applications of agent in scheduling, control, and enterprise integration and supply chain management. The focus of the paper is on how agent technology can be further developed in the support of collaborative process planning as well as its future research issues and directions in process planning. The current research directions in computer aided process planning (CAPP) and issues in traditional CAPP approaches are also discussed. Three agent-based approaches for process planning are presented. Finally, the key issues in developing agent-based collaborative process planning systems are summarized. <s> BIB011 </s> A review on integrated process planning and scheduling <s> Agent-based approaches of IPPS <s> This paper conceptualizes a bidding-based multi-agent system for solving integrated process-planning and scheduling problem. The proposed architecture consists of various autonomous agents capable of communicating (bidding) with each other and making decisions based on their knowledge. Moreover, in contrast to the traditional model of integrated process-planning and scheduling problem, a new paradigm has been conceptualized by considering tool cost as a dynamic quantity rather than a constant. Tool cost is assumed to comprise tool-using cost and its repairing cost. The repairing cost is considered to depend on the tool-breaking probability, which is predicted by the data-mining agent equipped with the virtues of C-fuzzy decision tree. When a job arrives at the shop floor, the component agent announces a bid for one feature at a time to all the machine agents. Among the machine agents capable of producing the first feature, one comes forward to become a “leader”, and groups other machine agents for the processing of remaining features of the job. Once all features are assigned to the appropriate machines, the leader then sends this allocation information to the optimization agent. The optimization agent finds optimal/near-optimal process plans and schedules via the hybrid tabu-SA algorithm. <s> BIB012
The concept of an agent came from the research of AI BIB011 . A typical definition of an agent is given by BIB001 as: "An agent is defined as referring to a component of software and/or hardware which is capable of acting exactly in order to accomplish tasks on behalf of its user". On the basis of the definition, one conclusion is that an agent is a software system that communicates and cooperates with other software systems to solve a complex problem that is beyond the capability of each individual software system . Therefore, the agent-based approach has been considered as one important method for studying distributed intelligent manufacturing systems. In the area of IPPS, the agent-based approach has captured the interest of a number of researchers. BIB007 reviewed the research on manufacturing process planning, scheduling as well as their integration. BIB008 provided a literature review on the IPPS, particularly on the agent-based approaches for the problem. The advantages of the agent-based approach for scheduling were discussed. BIB011 reviewed the agent technology for collaborative process planning. The focus of this research was on how the agent technology can be further developed in support of collaborative process planning as well as its future research issues and directions in process planning. BIB002 proposed a Multi-Agent System (MAS) where process routes and schedules of a part were accomplished through the contract net bids. IDCPPS BIB003 ) was an integrated, distributed and cooperative process-planning system. The process-planning tasks were separated into three levels, namely initial planning, decision-making and detail planning. The results of these three steps were general process plans, a ranked list of near-optimal alternative plans and the final detailed linear process plans, respectively. The integration with scheduling was considered at each stage with process planning. BIB004 presented a computerised model that can integrate the manufacturing functions and resolve some of the critical problems in distributed virtual manufacturing. This integration model was realised through a multi-agent approach that provided a practical approach for software integration in a distributed environment. Zhang (2003, 2004 ) introduced a multi-agent-based framework for IPPS. This framework could also be used to optimise the utilisation of manufacturing resources dynamically as well as provide a platform on which alternative configurations of manufacturing systems could be assessed. BIB005 developed an MAS-based approach to study the IPPS in collaborative manufacturing. BIB006 proposed a new methodology of DPP. It focused on the architecture of the new approach, using multi-agent negotiation and cooperation, and on the other supporting technologies such as machining-feature-based planning and function-block-based control. BIB009 BIB010 ) developed an online hybrid-agent-based negotiation MAS for integrated process planning with scheduling/rescheduling. With the introduction of the supervisory control into the decentralised negotiations, this approach was able to provide solutions with a better global performance. BIB012 presented a bidding-based MAS for IPPS. The proposed architecture consisted of various autonomous agents capable of communicating (bidding) with each other and making decisions based on their knowledge.  proposed a new method in IPPS. A multi-agent-learning-based integration method was devised in the study to solve the conflict between the optimality of the process plan and the production schedule. In the method, each machine made decisions about process planning and scheduling simultaneously, and it had been modelled as a learning agent using evolutionary artificial neural networks to realise proper decisions resulting from interactions between other machines.  proposed an agent-based architecture of an IPPS system for multi-jobs in flexible manufacturing systems. In the literature of agent-based manufacturing applications, many researches applied with simple algorithms such as dispatching rules are applicable for real-time decision-making . These methods are simple and applicable, but they do not guarantee the effectiveness for complex problem in the manufacturing systems. As the efficiency become important in the agent-based manufacturing, the recent research works are trying to combine the agent-based approach with other techniques such as GA, neural network and some mathematical modelling methods . Therefore, one future research trend is presenting more effective algorithms to improve the effectiveness of agent-based approaches. On the basis of the above-mentioned comments, one conclusion can be made that the agent-based approach is an effective method to solve IPPS. Because single-agent environments cannot solve the problem effectively, MAS is more suitable to solve it BIB011 . Although the architecture and the negotiation among agents may be very complex, MAS will have a promising future in solving this problem BIB009 BIB011 .