Advanced Planning And Scheduling Systems Research Articles

Advanced planning and scheduling technology

This article presents research on the core technology in advanced planning and scheduling (APS) systems that are currently the state-of-art in supply chain planning and optimisation. Further research is needed to enable the opportunities given, especially the area of combined planning and scheduling. Mixed integer linear programming (MILP) methods have been successfully applied to solve diverse problems, such as planning and capital budgeting. Constraint programming (CP) methods have proved to be successful in solving highly constrained discrete optimisation and feasibility problems for scheduling and resource allocation and have been combined with MILP and titled Mixed linear logic programming (MLLP). In this article an integrated approach is presented that uses the complementary strengths of MILP and CP for solving problems that are otherwise intractable using either of these two methods alone. The presented optimisation approach can effectively handle the combined planning and scheduling problem within an APS system as part of the core optimisation engine.

Levantamento das práticas de programação detalhada da produção: um survey na indústria paulista

Devido à grande instabilidade dos mercados e a intensa competição entre as empresas, a Programação Detalhada da Produção (PDP) vem se tornando cada vez mais um desafio para a gestão empresarial. As empresas, na busca do aprimoramento das atividades de PCP, estão demandando ferramentas de programação finita, também conhecidas como Advanced Planning and Scheduling (APS). Este artigo visa identificar as necessidades e dificuldades da programação detalhada da produção, as barreiras de implantação e os benefícios dos sistemas APS. O método utilizado foi um survey com as empresas filiadas à Fiesp. Os resultados obtidos mostram: i) a programação detalhada da produção é efetivamente uma atividade complexa para a maioria das empresas, especialmente aquelas com estratégia de produção contra pedido (MTO-make to order); ii) a maioria das empresas ainda utiliza o modelo MRP (capacidade infinita); iii) os objetivos de melhoria de desempenho na entrega poderiam ser mais facilmente alcançados com o uso de sistemas APS; iv) o investimento financeiro e falta de capacitação são ainda impedimentos para a implantação desses sistemas.

The potential benefits of advanced planning and scheduling systems in sales and operations planning

PurposeThe purpose of this paper is to explore what potential benefits may be achieved by using advanced planning and scheduling (APS) systems in the sales and operations planning (S&OP) process.Design/methodology/approachThe paper investigates benefits at the S&OP process level by interviewing APS experts and APS users. Several methods have been used; literature review, Delphi study, and a case study at a company in the chemical industry which uses APS system support in the S&OP process.FindingsThree types of potential benefits were found to be achieved when using APS systems in the S&OP process; benefits concerning decision support, planning efficiency and learning effects. The most common type was decision support benefits according to APS users and APS experts. The results from the case company showed that the benefits perceived in the different S&OP activities differed. In the activities concerning the preparation and generation of delivery plans, the perceived benefits mainly concerned learning effects. In the activities concerning the generation of a production plan, the benefits were foremost found in planning efficiency. In the S&OP meeting decision support benefits were highest valued. The reason for the different results can be explained by the aim of the activity, how APS was used in the activity, the user characteristics and the design of the model and access and quality of planning data.Research limitations/implicationsThe focus of this paper is on potential benefits of APS systems in the S&OP process only, not the costs. It has established a typology of potential benefits. No validation in form of statistical analysis has been done. The empirical analysis is mainly based on findings from a single case study.Practical implicationsThe findings about the types of APS potential will assist companies in understanding the benefits they can expect from its use in the S&OP process. The case study analysis gives further insight into how APS can be employed and what benefits different APS user categories can expect when it is used in an appropriate way.Originality/valueThe knowledge about which benefits that can be achieved when using APS in the S&OP process is quite unexplored. This paper fills some of these gaps.

The relationship between shop floor autonomy and APS implementation success: evidence from two cases

In companies where Advanced Planning and Scheduling (APS) systems are implemented, planning and scheduling decisions are often transferred from the shop floor to the new APS system. As a result, there can be disagreement between the scheduler and the shop floor about the amount of autonomy permitted on the shop floor post implementation. When this is the case, it often leads to problematic use of APS. Until now, the relationship between this production control concept and its implementation has hardly been studied. This article presents two cases where the relationship between autonomy and APS success is investigated. The cases represent two extremes in terms of the level of autonomy and the effect that this has on the success of APS implementation. The results show that although different divisions of autonomy are feasible in a specific situation, a disagreement concerning autonomy is a key explanatory factor for understanding why an APS implementation may fail.

Multi-tier and multi-site collaborative production: Illustrated by a case example of TFT-LCD manufacturing

To seek collaboration with other partner enterprises becomes an inevitable strategy in today’s highly dynamic and complex business. Production planning over a collaborative network relies on resolving three challenges: (1) different objectives and autonomy of partner enterprises, (2) communication and coordination among the enterprises, and (3) planning over multiple tier enterprises and multiple local plants (sites) inside an enterprise. To resolve the challenges, this paper proposes a distributed production planning system for a multi-tier and multi-site production system by combining agent technology with advanced planning and scheduling (APS) system. Two types of agents are designed: one for each tier enterprise (tier agent) and the other for each local plant (site agent) inside a tier enterprise. While a tier agent is responsible for finding a suitable plan for the demand orders by transmitting messages through designated protocols with its downstream and upstream tier agents, a site agent is designed for detailed production schedules for its local plant by interacting with its tier agent and its APS system. This paper has developed various protocols to integrate the partner tier and site agents to construct a distributed collaborative production system. This paper takes TFT-LCD manufacturing as an illuminative example to demonstrate the feasibility of the proposed multi-tier and multi-site collaborative production. The results show the feasibility of synthesizing multiple production plans over multiple enterprises and multiple production sites. Within the planning system, each company maintains their autonomy of production decision. Besides, the supply network is reconfigurable because the participated companies only need to comply with the protocols without changing their local legacy production planning systems.

Advanced planning and scheduling systems in aluminium conversion industry

Standard software packages, known as advanced planning and scheduling systems (APS), are often implemented to compute feasible production plans that can take into account several constraints (such as resources capacity), at different decision levels. In this research, emphasis is put on studying the relevance of APS principles in the specific area of the aluminium conversion industry (ACI). In this particular case, the characteristics of the processes involved (e.g. casting and rolling) are such that certain principles used by APS (e.g. finite capacity scheduling, constraint-based planning, bills of materials) may cause problems. This article extends a previous study related to the relevance of enterprise resource planning (ERP) systems for ACI in the direction of APS. It aims at identifying benefits, but also limitations and problems, which may arise when implementing this type of system. In this respect, the main features of APS systems are recalled. Specific features of ACI that are likely to cause problems are identified. It is shown that, if APS are indeed attractive, in certain cases important limitations exist, which can significantly affect the performances (e.g. increasing the lateness of product delivery, overproducing or increasing scrap and inventories). Several results presented in the current article can be relevant for other types of process industries.

Integrated data structure and scheduling approach for manufacturing and transportation using hybrid genetic algorithm

The scheduling systems in industries are required to construct schedule considering many kind of elements. The Advanced Planning and Scheduling (APS) is an approach for combined problems. To realize APS system, it is important to integrate data structure and scheduling algorithm using these data. In this paper, we propose integrated data structure based on Bill of Manufacturing with information technology of XML family and new Multistage Operation-based Genetic Algorithm for scheduling subsystem. The results of numerical experiment validate effectiveness of the proposal methods.

A Conceptual Framework of an Advanced Planning and Scheduling System for Printed Circuit Board Manufacturing Lines

Advanced planning and scheduling (APS), which is one of the most advanced technologies in manufacturing management applications, is emerged to resolve the shortcomings of enterprise resource planning (ERP) systems and manufacturing execution systems (MES) as a planning and scheduling tool. In this paper, we suggest a conceptual design of an APS system, specific for printed circuit board (PCB) manufacturing lines. In general, the PCB line can be regarded as a hybrid flow shop in which there are serial workstations, each with unrelated parallel machines, and has special characteristics such as complex and re-entrant flows, high and sequence-dependent setup times, subcontracting in the operation level, etc. Although there are a number of commercially available APS packages, they are not directly applicable to the PCB lines due to these characteristics. Therefore, we suggest a new conceptual design of APS, called PCB-APS in this paper, which consists of five modules: work module, simulation run module, dispatching rule generation module, simulation model generation module, and master data input module. The PCB-APS suggested in this paper considers the characteristics of the PCB lines in more details, and hence can improve the system performances significantly.

Zur Ausdrucksstärke der Stammdaten des Advanced Planning and Scheduling

Expressiveness is applied to evaluate languages or descriptions. By expressiveness we mean what can be said within the limitations of some language. Assessing expressiveness is always based on a reference, namely the set of all things sayable, the things said in another language or the things that must be said to meet a certain purpose. So far, only nominal or ordinal measures of expressiveness have been proposed. In the approach presented here, a certain purpose serves as reference to evaluate expressiveness by a cardinal measure. The approach is derived from measuring similarity between binary vectors and employs results concerning the formal semantics of logical descriptions. By applying this approach to measure the expressiveness of the master data used by Advanced Planning and Scheduling (APS) systems on the one hand and Enterprise Resource Planning (ERP) systems on the other hand it can be shown that in most cases the master data of APS systems do not possess higher expressiveness than the master data of ERP systems.

A case study on the integration of APS and ERP in a steel processing plant

This article describes the implementation of information systems to support the production planning and scheduling functions in two steel processing business units of a steel plant. In particular, the integration of the implementation of two systems is described: Enterprise Resource Planning (ERP) and Advanced Planning and Scheduling (APS). The article presents a functional architecture that integrates the two systems, and discusses typical issues that have to be solved when ERP and APS systems have to be integrated. Lessons learnt included the importance of an architecture to facilitate discussions, issue management, the importance of the primary process, differences between an ERP and APS implementation and differences in process descriptions.

Robust scheduling in an advanced planning and scheduling environment

A new scheduling problem that appears in an advanced planning and scheduling (APS) environment is discussed. Under the precondition that all materials are available when needed, the problem is formulated as follows: min N i =1 ( D i - E i )/N subject to D i - C i S 0, for all i , where N is the number of customer orders arriving randomly at the shop during a certain period, D i is the estimated due-date for customer order i , E i is the due-date estimation time for customer order i and C i is the completion time for customer order i . Then, D i and C i are endogenous variables and E i is an exogenous variable. The ability to construct a flexible scheduling process that avoids the need to fix ongoing schedules is essential to all APS systems. Therefore, the concept of a due-date buffer is introduced which is expected to enable the production schedules for each customer order to be flexible at the beginning and gradually become fixed as the processing of the order progresses. A simulation-based scheduling algorithm using the concept of a due-date buffer is developed here and subsequently examined through a series of numerical experiments. The obtained computation results show that the performance of due-date buffers is outstanding with respect to complicated production processes having higher utilizations.