Visszutas logisztika és termeléstervezés (Reverse logistics and production planning)

A dolgozat a visszutas logisztikát, az újrahasznosítást igyekszik beilleszteni a vállalati termeléstervezés keretei közé. A szükséglettervezési rendszerek (material requirements planning, MRP) célja a készletek és beszerzendő anyagok, alkatrészek időben ütemezett gyártásának és beszerzésének megtervezése. A klasszikus MRP rendszereket az utóbbi időben próbálja a tudomány az újrahasznosítással kibővíteni. Mivel ebben az esetben az új, és újrafelhasználható anyagokat külön kell nyilvántartani, ezért az MRP-táblák és készletek növekednek. A rendelési tételnagyságok meghatározása is nehezebb, összetettebb tételnagysághoz vezet. A dolgozatban egy visszutas logisztikai készletmodellt ismertetünk, valamint annak dinamikus kiterjesztését, amely alapja lehet az SAP-ba beépíthető rendelés állomány meghatározó heurisztikának. ____ The aim of the paper is to extend production planning with reverse logistics and reuse. Material requirements planning (MRP) systems plan and control invetory levels and purchasing activities of the firm. In the last decade scientists on this field try to involve reverse logistics activities in MRP systems. Size of MRP-tables is growing in this case because of the alternative use of newly purchased products and reusable old items. Determination of order quantities will be more complex with these two modes of material supplies. An EOQ-type reverse logistics model is presented in the paper with a dynamic lot size generalization. The generalized model can be seen as a basic model to build in production planning and control system like SAP

Analisis Penerapan Metode Material Requirement Planning (MRP) dalam Perencanaan dan Pengendalian Bahan Baku pada PT. BSM

PT. BSM, is a company that operates in the manufacturing sector by producing Mechanical Seals and is also a distributor of the Nippon Pillar Japan brand. Production planning and control is necessary to ensure that all processes function smoothly and production efficiency and effectiveness are achieved. PT.BSM's production system implements Make To Order (MTO), in which production activities are carried out when the customer places an order. This process will take place from raw materials, and semi-finished goods to finished products. This will pose a risk to the production process if the raw materials to be produced are not yet available. So it is necessary to have an analysis of planning and inventory control to expedite the production process. Therefore, the purpose of this study is to plan and control raw materials in accordance with requests from customers in the future using the Material Requirement Planning (MRP) method with the Lot For Lot (LFL) technique, after calculating the MRP with The Lot For Lot (LFL) technique obtained the planning results for mechanical seal raw material requirements for 2023 every month. Based on MRP calculations using the Lot For Lot technique, mechanical seal raw materials can be planned and controlled for the next 12 periods.            Key Words: LFL, Mechanical Seals, MRP,  Supplie

A flexible architecture for manufacturing planning software maintenance

Computer software systems took on a new role in manufacturing planning with the introduction of Material Requirement Planning (MRP) system in 1965. The MRP system generates material requirement lists in response to given production requirements. In this way, inventory management, purchasing, and shipping activities are linked to manufacturing. In 1979, Manufacturing Resource Planning (MRP II) systems were introduced [VerDuin 1995]. MRP II typically includes planning applications, customer order entry, finished goods inventory, forecasting, sales analysis, production control, purchasing, inventory control, product data management, cost accounting, general ledger processing, payables, receivables, and payroll [Turbide 1995]. An emerging market is developing for software systems that expand the scope of\u27MRP II farther to encompass activities for the entire organization. Among these systems are Enterprise Resource Planning (ERP), Customer-Oriented Manufacturing Management System (COMMS), and Manufacturing Execution Systems (MES). These systems integrate marketing, manufacturing, sales, finance, and distribution to move beyond optimizing production alone, to optimizing the organization\u27s multiple objectives of low cost, rapid delivery, high quality, and customer satisfaction [VerDuin 1995]. MRP II is still the dominant solution for manufacturing in tens of thousands of companies. These companies range in size from less than a million dollars in sales right up to the top of Fortune 500 companies. However, this is a market penetration of only 11% which clearly shows the size and potential of the opportunity for MRP II development. Yet, despite the commonality of needs across the scope of manufacturing, there are distinct differences when comparing plant to plant, company to company, and industry to industry. Often MRP II has to be modified to adapt to a particular industry [Turbide 1993]. This modification often pushes the cost even higher and makes MRP II more out-of-reach for many companies. Therefore, it would be highly beneficial for the overall scope of manufacturing if a highly flexible low-cost MRP II system can be developed. This research presents a flexible architecture for development and maintenance of manufacturing planning software, especially MRP II. The architecture uses the concept of software reuse and is built on top of run-time object-oriented framework

An integrated MRP and finite scheduling system to derive detailed daily schedules for a manufacturing shop

Many companies rely on Material Requirements Planning (MRP) to support their Production Scheduling and Control (PS&C) functions. Since MRP does not provide a detailed shop floor schedule, these users have to implement either a third party procedure or an internally developed procedure for shop floor controls. In this thesis we consider a class of user shops which are characterized by the following features: Homogenous machines, that is all machines can produce all products. Each product requires a setup, but several products may have a common setup. MRP requirements are specified on a weekly basis while actual requirements are specified on a hourly basis. Specifically, we develop a MRP and Finite Scheduling System (MFSS) which calculates the weekly net change requirements of products, then generates the detailed daily job order schedules, and finally sequences jobs on machine queues. The objectives of the system are to maximize the utilization of the machines and to minimize setup times. The MFSS was programmed on a personal computer-based system utilizing off-the-shelf relational database software

Exploring applicability of the workload control concept

To be successful in companies, a production planning and control (PPC) concept should fit to the production environment. Essential elements of the concept should correspond with the characteristics of the production system. For classical concepts such as MRP these elements have become common sense. For example BOMexplosion and constant lead times make MRP known to perform best in environments with high material and low capacity complexity. For many other concepts the situation is less clear. In this paper the Workload Control (WLC) concept is considered for which the requirements for a successful application have never been investigated. A framework is proposed to explore the applicability of WLC in small- to medium-sized make-to-order (MTO) companies. It supports an initial consideration of WLC in the first phase of a PPC selection and implementation process. As a first step in developing the framework the inherent characteristics of the WLC concept and the relevant MTO production characteristics are identified. Confronting the indicators of the company characteristics with the WLC elements results in bestfit indications for the WLC concept. Contrarily to other PPC evaluation schemes the framework considers variability indicators besides averages. Use of this framework for a medium sized MTO company demonstrates its suitability in getting a systematic and quick impression of the applicability of WLC. Essential elements are treated and assessed.

Optimizing Production Process through Production Planning and Inventory Management in Motorcycle Chains Manufacturer

Based on the data, there were still shortages of production from year to year and demand were unstable in motorcycle chains manufacturer in Indonesia. To overcome these problems, the purpose of this research was to make production planning and inventory control consisting of forecasting, aggregate planning, Master Production Schedule (MPS), and Material Requirements Planning (MRP). Forecasting used the additive decomposition method (average of all data), multiplicative decomposition (centered on moving average), and winter method (additive and multiplicative). Aggregate planning used chase strategy, level strategy, and transportation model. Moreover, MRP used lot for lot, Economic Order Quantity (EOQ), and Periodic Order Quantity (POQ) methods. The test shows several results. First, the best forecasting is additive decomposition (average of all data) with MAD value of 3.033,57, MSE with 13.590.490, and MAPE with 10,083%. Second, the best aggregate planning is transportation model with the total cost of Rp7.708.398.390,00. Last, the best MRP method is the lot for lot with total cost Rp7.162.567.653,00

Decision in Implementation of Production Capacity Planning Determinated by Usage of Sensitive Analysis

Purpose of article: Effective planning and management of material flow and production resources, i.e. production planning and control is generally regarded as crucial for the success of manufacturing companies. It involves managing all aspects of production, including materials management, planning and scheduling of machines and human resources and coordination of suppliers and key customers. They were followed a more advanced concept MRP II, controls all production resources. Despite production planning using ERP systems, based on MRP II logic. With this tool can company effectively balance all production resources and in the optimal way to schedule production orders according to production capacity. Implementation of capacity planning in the company introduces a number of problems associated with the requirements of quality information and accurate data on which is a production plan created. Decision on the implementation of capacity planning is a challenge associated with high risk and the need to consider the order of several months in advance uncertainty. At points where we do not have full control over decisions, it can be used heuristic methods of decision-making through a decision tree using the known probabilities, and with a partial ignorance of using interval arithmetic. Methodology/methods: Solving within decision tree with known probabilities obtained from expert in capacity planning. Scientific aim: Find the upper limit worth of implementation of capacity planning or MRP-II. Findings: The difference between the implementation the APS and MRP-II based on profits determinate by time. Conclusions: Enterprise should have after implementation of its own data to the model make decision of what kind of capacity planning is profitable for its purpose

Analysing the implementation of a material requirements planning (MRP) system into an engineer-to-order (ETO) company ; the case of National Oilwell Varco Norway (NOVN)

Masteroppgave økonomi og administrasjon- Universitetet i Agder, 2014A material requirements planning (MRP) system is a computer-based planning and control system whose main objectives are to provide the right part at the right time, and to meet the schedules for completed products. The development of these systems revolutionised the manufacturing industry, and lead to it being adopted by many companies. The expectations of the systems were high, both from academia and industry in the subject area of production planning and control. However, the widespread use of the system has uncovered several failures, mainly because the systems are implemented under the assumption that “one-size-fits-all”, and thus do not differentiate between various operations strategies. Prior research has already identified MRP systems as successful production planning and control systems in several operations strategies. Despite its importance, the previous research on MRP systems has not thoroughly addressed the systems strategic fit with an engineer-to-order (ETO) operations strategy. This thesis therefore focuses on the use of an MRP system in an ETO environment, and the overall objective is to investigate if implementation of an MRP system supports the operations strategy of an ETO company. To help investigate the overall objective, a literature review and a case study has been conducted. The literature review was carried out to provide a theoretical base for the research and a foundation for the future work of the research. A case study was conducted to help get a better understanding of an MRP system’s strategic fit in an ETO company to draw parallels between theory and practice. Numerical data has been collected to conduct statistical analysis. The case study company is a large ETO company that is about to implement an MRP system and that previously have used a similar system in some of its departments. Qualitative data from the case study have mainly been conducted through interviews and informal conversations with key informants employed in the case study company. The result of this research shows that there is a clear misalignment between the decision support provided by an MRP system and the decision support required by an ETO company. The product-, market- and process characteristics of an ETO company are too much of a constraining factor for the MRP system, which may lead to reduced competitiveness. Furthermore, the research suggests that organisational factors, such as education level of employees, company size and culture have significant impacts on implementation of an MRP system. The results gathered from the research have a foundation from relevant theory, which strengthens the quality of the thesis. The thesis has therefore contributed with increased knowledge and provides a better understanding of the use of an MRP system in an ETO company. In particular the definitions in the thesis, the identified variables, and the frameworks should be of interest for researchers, management, and consultant in the area of production planning and control (PPC). The research also has important implications for top management and policy makers in implementing an MRP system, as these stakeholders need to communicate effectively with their organisation about their MRP adoption intentions. Case study findings suggest that MRP systems are not suitable for ETO products, and that MRP implementation is influenced by, but not necessarily bound by, existing national and organisational factors. The findings of this study aid the management of organisations that are implementing MRP systems to gain a better understanding of the likely challenges they may face and enables them to put in place appropriate measures to mitigate the risk of implementation failures

An efficient production planning approach based demand driven MRP under resource constraints

Production plans based on Material Requirement Planning (MRP) frequently fall short in reflecting actual customer demand and coping with demand fluctuations, mainly due to the rising complexity of the production environment and the challenge of making precise predictions. At the same time, MRP is deficient in effective adjustment strategies and has inadequate operability in plan optimization. To address material management challenges in a volatile supply-demand environment, this paper creates a make-to-stock (MTS) material production planning model that is based on customer demand and the demand-driven production planning and control framework. The objective of the model is to optimize material planning output under resource constraints (capacity and storage space constraints) to meet the fluctuating demand of customers. To solve constrained optimization problems, the demand-driven material requirements planning (DDMRP) management concept is integrated with the grey wolf optimization (GWO) algorithm and proposed the DDMRP-GWO algorithm. The proposed DDMRP-GWO algorithm is used to optimize the inventory levels, shortage rates, and production line capacity utilization simultaneously. To validate the effectiveness of the proposed approach, two sets of customer demand data with different levels of volatility are used in experiments. The results demonstrate that the DDMRP-GWO algorithm can optimize the production capacity allocation of different types of parts under the resource constraints, enhance the material supply level, reduce the shortage rate, and maintain a stable production process