Cumulative figures principle

The cumulative quantity enprinzip 's business administration a specific method for the determination of production and supply orders, in which only the accumulated during a defined period target and actual amounts to be compared. This method is mainly used to control and synchronize production and delivery in the automotive industry and in large-scale production where there is a continuous demand.

Cumulative figure and control cycle

The cumulative number principle uses the systematics of the control loop . First, the required production or delivery quantities are added up on a time axis with defined time intervals, resulting in a cumulative curve. For each time interval, the target value (e.g. quantity to be delivered) is compared with the actual values (quantity actually delivered). The last or just delivered or produced quantity is not decisive, but only the total or accumulated quantity up to that point. Any deviation between the cumulative target and actual values is compensated for by the following production or delivery order: In the event of overdelivery / overproduction , the next order quantity is reduced or the next order date is postponed. In the event of under-delivery / under-production, the next order quantity is increased or the order date is brought forward.

To 'calm down' production and the flow of materials, tolerance limits for TARGET-ACTUAL deviations can be defined so that no new orders are generated in the event of minor deviations; A new order is only triggered when the tolerance limit is 'exceeded', otherwise the old order remains.

The control loop principle cannot recognize whether the target values or the actual values are correct, which can lead to material bottlenecks or high excess stocks. To check the material flow, however, an alarm message can be generated that indicates a possible error or problem at an early stage. For this purpose, certain metering points in the material flow (e.g. in the warehouse, incoming or outgoing goods) are defined as limit values that the actual values must not exceed or fall below. If this is the case, however, a corresponding warning is generated. The responsible employee must then check what caused the violation of the limit value. This deviation can be correct and can be understood, or there is a problem in the process or an error in the data or in the product documentation. Examples of errors: false independent requirements , a bill of error , no or late data collection , a calculation error, no or late Committee capture, installation of the wrong parts or assemblies in the production process.

Cumulative number and metering points

The target / actual comparison is based on defined metering points along the value chain . The metering points delimit the successive material flow intervals, which are also referred to as 'control blocks'. When defining the production and material flow structure, it must be ensured that the intervals do not overlap and that no intervals are missing. When collecting data, it must also be ensured that a product or material does not run through an interval multiple times and that no interval is omitted, because otherwise the product or material will be counted twice or not at these metering points and the actual values will therefore be incorrect.

The target required quantities are determined one after the other at the defined metering points by shifting the requirement from one metering point to the next metering point with the help of the throughput time , so that the required quantities can also be calculated consistently for extended production and supply chains. The actual quantities of the products and materials flowing past are also recorded at the metering points. As a result, the TARGET and ACTUAL quantities at the successive metering points (in the direction of material requirements / consumption) have to decrease continuously, which can be read from a 'progress figure' diagram.

Cumulative quantity and stock level

By comparing the cumulative required quantities at successive metering points, it is possible to determine which quantities are between the metering points (in the interval), whereby all 'stocks' in the entire production and transport chain (e.g. the warehouse stock , the operational circulation or material on transport ...) transparently. A warehouse stock results from the difference between the cumulative warehouse receipt and the cumulative warehouse output and is mainly determined by the warehouse lead time. The stock level can be specifically influenced via an additional control parameter 'warehouse safety time'. If the specified total warehouse cycle time is greater than the actual storage duration, physical inventory is created; if the specified total warehouse cycle time is less than the actual storage duration, there is a bottleneck or shortage in the warehouse.

In contrast to the gross-net invoice, the inventory does not play a role in the cumulative figure principle, so it is not deducted from the calculated gross demand. For the cumulative quantity principle, the respective warehouse stock does not play a role, rather only the difference between the cumulative target and the cumulative actual at the warehouse receipt or the goods receipt is considered. With the cumulative figure principle, errors in the process or in the data acquisition are not compensated for by the inventory, as is the case with the gross net invoice. In order to identify problems at an early stage and to avoid bottlenecks in the material supply, warning messages (alerts) are generated in the event of 'unusual' deviations. In this way, upper and lower limits can be set for the inventory; as soon as these are exceeded or not reached, a warning is issued and the responsible employee (e.g. a dispatcher ) can then check whether there are real delivery problems or whether there is a possible recording error in the warehouse or whether an incorrect requirement calculation or a parts list error The reason for the warning is.

Cumulative figure and supply chains

The cumulative figures are part of the VDA messages for the transmission of requirements between the automobile manufacturers and suppliers (see delivery schedule ). The cumulative required quantities for the agreed metering points are exchanged between the manufacturers involved and their suppliers via EDI . Up to now, the incoming goods department at the OEM has usually been chosen as the common point of delivery , because the accuracy of recording is particularly good here. With the new delivery and logistics concepts, the goods issue at the supplier is now also selected in order to identify target-actual deviations at an early stage. With the advance calculation with the help of the lead times, an extensive production and material flow (see also the supply chain ) can be consistently planned and monitored, which at the same time largely avoids a whip effect .

literature

Wolfgang Heinemeyer: Planning and control of the logistic process with progress figures. In: D. Adam (Ed.): Flexible manufacturing systems. Gabler Verlag, Wiesbaden 1993, ISBN 3-409-17914-3 , pp. 161-188.

Wilmjakob Herlyn: The Bullwhip Effect in expanded Supply Chains and the Concept of Cumulative Quantities . epubli, Berlin 2014, ISBN 978-3-8442-9878-9 , pp. 513-528 .

Michael Schenk, Rico Wojanowski: Progress figures . In: Reinhard Köther: Taschenbuch der Logistik. 2nd Edition. Hanser Verlag, Munich 2006, ISBN 3-446-40670-0 .

Hans-Peter Wiendahl: Production control - logistical control of production processes based on the funnel model . Hanser, Munich 1997, ISBN 3-446-19084-8 .

Hans-Peter Wiendahl: Business organization for engineers . 7th edition. Hanser, Munich 2010, ISBN 978-3-446-41878-3 .

Hermann Lödding: Process of production control. 2nd Edition. Springer Verlag, Berlin / Heidelberg 2008, ISBN 978-3-540-76859-3 .

Paul Schönsleben: Integral logistics management . 7th edition. Springer Vieweg, Berlin Heidelberg 2016, ISBN 978-3-662-48333-6 .

Individual evidence

↑ H. Lödding: method of production control. Springer Verlag, 2008, chap. 13.
↑ Paul Schönsleben: Integrales Logistikmanagement , Springer Vieweg Verlag, 7th edition, 2016, p. 308
↑ H.-P. Wiendahl: Production control. Hanser, 1997, p. 344 ff
↑ H.-P. Wiendahl: Business organization for engineers. Hanser Verlag, 2010, p. 337 ff.
^ W. Herlyn: The Bullwhip Effect in expanded Supply Chains and the Concept of Cumulative Quantities. epubli Verlag, Berlin 2014, ISBN 978-3-8442-9878-9 , pp. 513-528.

[1] H. Lödding: method of production control. Springer Verlag, 2008, chap. 13.

[2] Paul Schönsleben: Integrales Logistikmanagement , Springer Vieweg Verlag, 7th edition, 2016, p. 308

[3] H.-P. Wiendahl: Production control. Hanser, 1997, p. 344 ff

[4] H.-P. Wiendahl: Business organization for engineers. Hanser Verlag, 2010, p. 337 ff.

[5] W. Herlyn: The Bullwhip Effect in expanded Supply Chains and the Concept of Cumulative Quantities. epubli Verlag, Berlin 2014, ISBN 978-3-8442-9878-9 , pp. 513-528.