Joachim Reese

Hierarchical Planning for Just-in-Time Deliveries

The just-in-time (JIT) delivery of products is a considerable challenge for many firms, because suitable planning methods have to be developed and practically installed. One main problem refers to the suppliers’ strategy, as they are no longer able to keep their optimal lot sizes and production rates due to customers’ reduced call-forward rates (cf. e.g. Fandel et al. 1988 and Fandel 1988). Thus, the suppliers have to choose different planning procedures in order to assure that there will be no avoidable in-process costs, as concerns particularly the production, inventory, and transportation of products. Obviously, there exist remarkable trade-offs between the design parameters of the whole process (cf. Reese 1991), which require a simultaneous optimization of all variables.

Cost minimization is a firm's power station

Energy represents for every industrial site a fundamental process input which can only be substituted with great difficulty and without which industrial manufacture in general is impossible. The requirement is hereby concentrated on the utilization of distinct types of thermal energy for the process steam and heating, as well as for power and light. According to WOLF (1987) the total demand in 1981 for energy for industrial purposes in the Federal Republic of Germany was divided as follows — 75.9% for the manufacturing process, 10.9% for space heating and 13.2% for power and light. Although several energy resources were used equally for the production of heat, power and light were generated almost without exception by means of electricity. Heat as well as power and light, or rather electricity, are all commodities which have only a limited storage capacity. This leads to considerable procurement problems when the energy requirement fluctuates.

Organization and Planning of Vehicle Utilization in a Chemical Firm

Within the framework of production planning the internal transport of goods, i. e. the transport between various locations within a work’s grounds, is attributed an auxiliary function which is becoming increasingly important on account of the growing spatial expansion of firms and because the production schedule is otherwise planned down to the last detail. In the forefront of these reflections is the task of planning the utilization of vehicles, in accordance with which — the transport demand and the number of available vehicles supposed as given — all orders must always be carried out efficiently. In order to efficiently accomplish all orders they should be carried out in such a way that all the routes and travel times are kept to a minimum and so that individual operations of the production process are not hindered by unpunctual execution.

Optimal Heat-Matched Cogeneration of Energy in a Firm Owned Power Station - A Case Study

Energy represents for every industrial site a fundamental process input which can only be substituted with great difficulty and without which industrial manufacture in general is impossible. The requirement is hereby concentrated on the utilization of distinct types of thermal energy for the process steam and heating, as well as for power and light. According to Wolf (1987) the total demand in 1981 for energy for industrial purposes in the Federal Republic of Germany was divided as follows — 75.9% for the manufacturing process, 10.9% for space heating, and 13.2% for power and light. Although serveral energy resources were used equally for the production of heat, power and light were generated almost without exception by means of electricity. Heat as well as power and light, or rather electricity, are all commodities which have only a limited storage capacity. This leads to considerable procurement problems when the energy requirement fluctuates.

Simultane Standort- und Belegungsplanung für Maschinen in mehrstufigen Produktionsprozessen

Interdependenzen zwischen verschiedenen Planungsaspekten der Produktion lassen sich in vielerlei Hinsicht aufdecken. Wertvolle Arbeit wurde geleistet, als unter dieser Erkenntnis beispielsweise versucht wurde, ein Maschinenbelegungsproblem simultan zur Bestimmung des Produktionsprogramms 1) oder der Losgrosen der Auftrage 2) zu losen. Dagegen fehlen in der Literatur solche Hinweise, die sich auf eine gemeinsame Betrachtung der Standort- und Belegungsoptimierung beziehen. Dies ist insofern verwunderlich, als die zahlreichen Formulierungen und Losungswege, die sich fur beide Problemstellungen anbieten, das jeweils andere Problem nicht auser acht lassen konnen.