STEM help / Calculation framework

Inputs beginning with ‘R’

Ratio of Charge

The variable component of STEM 5.0 Working Capital the proportion of a Service’s Operating Charge which is required as working capital, in addition to the Base Level.

Default: 0.0.

Reallocation of Costs

A choice governing how the costs of slack Resource capacity are allocated between the Services which previously used it.

No: the costs of newly-slack capacity of a Resource are allocated according to each Service’s historical usage of that Resource; but the allocation of the costs of existing slack capacity remains unchanged.

Yes: the costs of all the slack capacity of a Resource are re-allocated each year, according to each Service’s historical usage of that Resource.

Default: Yes.

Decommissioning Mode

Default: Annual Proportion

Decommissioning Proportion

The proportion of any redundant units of a resource that are removed from the network each year. This can be used in conjunction with Churn Proportions to model early decommissioning.

Default: Constant {0.0}. Redundant units remain in the network.

Reference Tariff

A tariff which qualifies the (reference) demand assumptions for a Service. The actual Penetration and Annual Traffic per Connection applied in the model are scaled from the input assumptions, according to proportional changes in the actual tariffs charged compared to the corresponding Reference Tariffs, to an extent governed by the respective Price Elasticities. Reference Tariffs are only required when a positive Price Elasticity has been defined.

Default: Constant {0.0}.

Rental Cost

The cost of leasing a unit of a Resource per period (as defined by the Cost Period input) in the Calibration Period, e.g., the rental cost of a leased line.

For a consumable resource, rental cost is the cost of using one unit, rounded up to a full unit, and generated in the period in which the capacity is installed.

Default: 0.0.

Rental Cost Trend

This is applied to the calibration value you set for Rental Cost in the Resource/Costs dialog.

Default: Constant {1.0}.

Rental Tariff

The tariff charged per period (defined by Tariff Period input) per connection to a Service.

Default: cost independent and Constant {0.0}.

Note: The simple Tariffs dialog just shows the Cost Independent Tariffs, which are also shown in the more detailed Cost Dependent Tariffs dialog.


The number of years’ grace before principal repayments (amortisation) begin. New borrowing is only allowed during this grace period.

Default: 0.


The Replicants box lists all the elements linked to the Template. It is these elements, and their structure, that will be replicated in the expanded model.

See 9.5 Managing complexity with template replication.

Default: none.

Residual Value

The price obtained for a Resource if it is possible to sell the asset when it is no longer needed. The used or scrap value of an asset should be modelled as residual value.

Default: 0.0.

Residual Value Trend

This is applied to the calibration value you set for Residual Value in the Resource/Costs dialog.

Default: Constant {1.0}.


The Resource from which the ‘size’ of a Transformation Input is derived, in conjunction with the Basis.

Default: <none>.


The Resources listed are those that perform the selected Function.

Double-clicking on the name of a Resource opens the data entry dialog associated with it.

You can also insert new Resources into the Function, or rename or delete existing ones from within this box.

See 4.4 Working with model elements, icons, links and text boxes


A set of results and features for which pertinent data should be reported in a run-time audit.

See 4.25 Auditing the calculation of results at run time.

Default: none.


       Buy SSL

© Implied Logic Limited