Production Planning Approach Research Articles

Improving economic efficiency of operating rooms: production planning approach

Managing surgical services efficiently is essential when maximising the produced health with limited resources. This study aims at understanding the efficiency of operating rooms from the production planning and control point of view. Economic efficiency measure that includes the process costs and output was developed and tested in a real-life context. Daily efficiency was mostly dependent on the number of used operating rooms (beta ?0.42, p < 0.01). Speed of surgery, number of delayed surgeries and planned utilisation rate also had an effect on the efficiency. Compared to the previous literature the role of staffing in improving operating room efficiency is emphasised.

An attainable region approach for production planning of multiproduct processes

AbstractA novel approach is presented for the solution of production planning problems for multiproduct processes. A mixed‐integer programming (MIP) scheduling model is analyzed off‐line to obtain a convex approximation of feasible production levels and a convex underestimation of total production cost as a function of production levels. The two approximating functions are expressed via linear inequalities that involve only planning variables yet provide all the relevant scheduling information necessary to solve the planning problem with high quality. A rolling horizon algorithm is also presented for generation (if necessary) of detailed schedules. © 2007 American Institute of Chemical Engineers AIChE J, 2007

Hierarchical approach for production planning and scheduling under uncertainty

In this paper, the simultaneous solution of production planning and scheduling problem is addressed through a hierarchical framework. The planning problem aggregates orders in the planning period and considers uncertainty utilizing a multi-stage stochastic programming formulation where three stages are considered with increasing level of uncertainty. The planning model includes material balances and time horizon constraints which involve a sequence factor to reflect the recipe complexity. Using a rolling horizon strategy, the production for the current stage is provided to the scheduling problem, which is solved using a continuous-time formulation. An iterative framework is developed to converge the planning and scheduling results before solving for the next period. The proposed approach is illustrated with a planning case study.

Fuzzy approach for production planning and detailed scheduling in paints manufacturing

Due to growing competition, small- and medium-sized companies face within supply chains the challenge of providing short and reliable throughput times while coping with uncertainties, especially concerning time parameters, in production planning and detailed scheduling. The application of fuzzy scheduling is an adequate way to model these uncertainties in a supply chain. The paper presents an approach for the fuzzy scheduling of hybrid flow shops based on the general multi-mode resource-constrained project-scheduling problem. The approach is validated in a case study of a small- and medium-sized enterprise producing paints in a batch production process.

Capacitated plant selection in a decentralized manufacturing environment: A bilevel optimization approach

Most facility selection and production planning approaches assume centralized decision making using monolithic models. In this paper, we address a capacitated plant selection problem in a decentralized manufacturing environment where the principal firm and the auxiliary plants operate independently in an organizational hierarchy. A non-monolithic model is developed for plant selection in the decentralized decision making process. The developed model considers the independence relationship between the principal firm and the selected plants. It also takes into account the opportunity costs of over-setting production capacities in the opened plants. The developed mathematical programming model is a two-level nonlinear programming model with integer and continuous decision variables. It was transformed into an equivalent single level model, linearized and solved by available optimization software. Computational examples are presented.

Implementing a pull system in batch/mix process industry through Theory of Constraints: A case-study

This paper aims at understanding how the pull production planning approach can be implemented in a batch-mix process business through the Theory of Constraints (TOC). The paper, after a brief review of the main streams of study on TOC, identifies the key academic and managerial issues discussed about the process industries. Among these, a major one concerns production and inventory management for different types of process industries and the need for a transition towards a pull approach. Thus, a case-study is presented, concerning a batch-mix process company, which applied TOC. The paper describes the main features of the process, as well as the key decisions and activities performed in such plant in order to lead the transition to a pull system through the implementation of DBR.

Managing Increasing Product Variety at Integrated Steel Mills

Intense market competition in recent years has made it increasingly important for integrated steel mills (ISMs) to differentiate themselves from competitors based on customer service, two key attributes of which are the duration and the reliability of order-fulfillment time. To improve responsiveness, some ISMs are shifting from a pure make-to-order system toward a hybrid make-to-stock, make-to-order system. They can then match certain customer orders to existing semifinished inventory, thereby reducing the time it takes to fill those orders. However, choosing which semifinished products to make to stock and how to manage their inventory are difficult problems. We developed an optimization model that one ISM implemented as a decision-support tool for choosing the designs of made-for-stock (MFS) slabs. Use of the model has reduced the number of MFS slab designs and increased the proportion of orders covered by those designs.

Modelling flow and jobbing shops as a queueing network for workload control

Workload control is an approach for production planning and control that attempts to manage manufacturing lead times rather than treat them as a forecasting problem. It is particularly appropriate for jobbing and flow shops in the make-to-order sector of industry. It is based on Little's well known formula in queueing theory that the time an arrival spends in the system is the average number in the system divided by the arrival rate. However, the workload control approach treats the jobbing shop as a single entity and thus ignores the complexities caused by competing jobs arriving at a work station at the same time thus forming queues. This paper describes how the job shop environment may be formulated as an open queueing network. It is computationally impossible to solve the model exactly if there are more than three or four work stations. Results for an exact Markov process model for a triangular configuration of work stations are described. Initial results suggest that treating each work station as an independent queueing system leads to significant under-estimation of the manufacturing lead times, even for such a simple manufacturing system. Some initial ideas on deriving an approximation of the exact model to cover larger systems are also discussed.

A HIERARCHICAL PRODUCTION PLANNING APPROACH TO WORK UNIT SCHEDULING IN THE COAL INDUSTRY

Mineral Resources EngineeringVol. 04, No. 01, pp. 51-69 (1995) No AccessA HIERARCHICAL PRODUCTION PLANNING APPROACH TO WORK UNIT SCHEDULING IN THE COAL INDUSTRYE.L. GILLENWATER, J.J. BERNARDO, and G.T. LINEBERRYE.L. GILLENWATERDepartment of Management and Marketing, University of Mississippi, Oxford, Mississippi, USA Search for more papers by this author , J.J. BERNARDODepartment of Management, University of Kentucky, Lexington, Kentucky, USA Search for more papers by this author , and G.T. LINEBERRYDepartment of Mining Engineering, University of Kentucky, 230 Mining and Mineral Resources Building, Lexington, Kentucky 40506–0107, USA Search for more papers by this author https://doi.org/10.1142/S0950609895000059Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractCoal mine planning has three distinct decision levels: (1) decisions made at the upper level of management that determine production requirements for specific mines, (2) decisions made at the middle management level, the mine level, that determine how the mine satisfies its production requirements, and (3) decisions made at the operating level of management, the sectional level, that determine the sequencing of machine movements at the face. Two linear programming (LP) models for accomplishing decisions at the first two levels are developed. Both LP models address the aggregate planning process. The first model, the mine production scheduling model, permits determination of monthly production and inventory levels. The objective is to minimize the monthly production and inventory holding cost of the schedule. The second model, the sectional production scheduling model, incorporates a quality blending requirement into the determination of the weekly sectional production and inventory levels. The objective of this model is to minimize the weekly production and inventory holding cost. FiguresReferencesRelatedDetails Recommended Vol. 04, No. 01 Metrics History PDF download

Hierarchical modeling approach for production planning : G. Harhalakis, R. Nagi, J.M. Proth, pp 31–36

Hierarchical modeling approach for production planning : G. Harhalakis, R. Nagi, J.M. Proth, pp 31–36

Hierarchical Production-planning Systems: Extensions and Modifications

This paper extends earlier hierarchical production-planning approaches initiated by Hax and Meal. The proposed model incorporates both functional and hierarchical interfaces simultaneously as encountered in practice, and assures feasibility and consistency among the decisions made at the different hierarchical levels of the firm. The problem of infeasibility which arises in disaggregating the aggregate production plan into detailed schedules is solved using goal programming at the product-family disaggregation level, and using branch and bound at the item-disaggregation level. The proposed approach minimizes backlogging regardless of the underlying cost structure of the problem at hand.