Dynamic Disposition

The individual fields in acadon_timber and their function in the context of Dynamic Disposition are described below. For a correct setup of the parameters, the respective local conditions have to be considered. Changes to the parameters require a basic mathematical understanding. For further explanations of the terms used, please refer to e.g. Bronshtein & Semendyayev, Handbook of Mathematics or similar works.

For explanations of the formulas used in Dynamic Disposition, please refer to the general explanations in the work by Gudehus (all formulae are taken from Gudehus, T.; Dynamische Disposition; 2nd edition; Springer Verlag Berlin Heidelberg 2006)

We recommend that you use the predefined parameters and the standard replacement scenario to get started. The following explanations should help you to adjust the parameters if necessary.

Inventory setup

The dynamic planning tab (in old versions "dynamic disposition") contains various basic parameters.

Max. Variation Coefficient

This field corresponds to the variable v_max in formula 4.6 of Gudehus, i.e., this is the maximum coefficient of variation for the forecast period demand. Affects the calculation of the dynamic smoothing factor. If the ratio of predicted dispersion to predicted demand is greater than the coefficient of variation it is used to limit mean variation.

Min. smoothing factor

This field corresponds to α_min in formula 4.6 of Gudehus, i.e., it is a minimum smoothing factor (which ultimately determines the maximum number of days smoothing should consider), e.g., 0.033 for the last 60 days. The calculation is done according to formula 5.3 of Gudehus from the desired number of days (or disposition periods) N with α_min=2/(N+1).

Max. Smoothing factor

This field corresponds to α_max in formula 4.6 of Gudehus, i.e., it is a maximum smoothing factor (which ultimately determines how many days the smoothing should minimally consider), e.g., 0.333 for the last 5 days. The calculation is done according to formula 5.3 of Gudehus from the desired number of days (or disposition periods) N with α_max=2/(N+1).

Smoothing range in days.

This field specifies how many days backward to check for a sale.

After calculating α_λ(i) according to formula 4.6 of Gudehus, it is checked if the demand of the item in the date range working date-"smoothing range in days" ... Work date - 1 is zero. If this is the case, α_λ(i) is fixed to α_max (this corresponds to the 2nd additional condition in formula (4.8) [Gudehus]).

Smoothing range RPT

This field is used only if the procurement time is not to be computed statically but dynamically. This can be defined per stockkeeping. It indicates how many deliveries are to be used for the computation (and corresponds thereby to the value N ("smoothing range of the replenishment lead time") in the computation of α_WBZ (i.e. the smoothing factor of the replenishment lead time) according to process documentation.

Daily Invt. Int. Rate %

This field corresponds to the variable zl_AT , i.e. the storage day interest rate (in % per working day) in the calculation of the optimal replenishment quantity. The value is calculated from the annual interest rate zl_anno by dividing it by the number of working days (i.e. approx. zl_AT=zl_anno/250 )

Inventory Ordinal Factor

This field corresponds to the variable f_LO in the calculation of the optimal replenishment quantity. In case of chaotic stock order it is 0.5 - in case of fixed stock order it is 1.

Additional Reorder Days

This field can be used to manually add a number of days to the calculated dynamic or static replenishment time, which may be required for logistical processes not recorded in the system.

Check current demand

If this field is checked the dynamic disposition will check whether the current demand in the replacement time (-stock) is higher than the calculated replenishment. In this case the replenishment ("supplied quantity") will be increased to the current demand (-stock).

In the Inventory Setup Page you can initilize the inventory setup with default values. For this choose the Init Dynamic Disposition action.

Stockkeeping Unit (SKU)

Replenishment procedure

In the Planning tab, the "Dynamic" option can be selected in the "Replenishment procedure" field of the inventory data (i.e. per article, storage location or variant). In this case, further parameters apply which will be taken from the replenishment scenario of the item (in case this is empty the scenario from the inventory setup will be used).

It is also possible to enter individual values in the "Dynamic planning" tab which are only applied to this SKU.

Threshold value reorder point

Prevents ordering when reorder levels are small.

strategic stock threshold

If a stock is to be either zero or greater than the strategic stock threshold, then enter a value here. This can be useful, for example, if small quantities are unsaleable, e.g. for rafters, stair railings or similar. If something is entered here and the replenishment quantity is greater than zero but less than the strategic stock threshold minus inventory, then the replenishment quantity will be replenished to the strategic stock threshold (minus inventory).

Replenishment-Scenarios

The scenario contains various parameters which are used for the replenishment of items where this scenario is assigned.

Required Deliverability %

The delivery capability of an article is the ratio, measured over a certain period of time, of the orders that have been fully served from the article stock to the total number of orders for this article.

Supply Order Costs

This field corresponds to the variable kNAuf and is used in the calculation of the optimal replenishment quantity according to Gudehu's formula 8.13. It is the replenishment order cost (in LCY per order) (i.e. fixed order cost per order).

Bin Location Cost Rate

The field corresponds to the variable kLP and is the storage bin cost rate per storage unit per day in MW.

Apply seasonal factors

Only if this switch is set to "yes" the seasonal factors are taken into account when calculating the order proposal.

Disposition period [WD]

This field specifies how often an item is ordered. With 1 it is assumed daily order, with 5 weekly order (with 5 working days).

Replacement Time Calculation

Here it can be set whether the replenishment time of an article is to be taken from the article card as in the standard of Microsoft Dynamics NAV ("static") or "dynamically" calculated according to the formulas of Gudehus for the computation of the replenishment time. If this field is set to "static", the field "Smoothing range WBZ" has no function.

Reorder no. of working days

If the procurement time is computed statically this value is set as procurement time.

Max. Inventory Range

The value entered here limits the replenishment quantity upward. It is ordered maximally so much as from the multiplication of maximum stock range and the prognosticated demand for the order period results. The field should therefore be set in order periods (e.g. days).