| # Using extensions An extension consists mainly of invoicing agreements. The relation to the budget is defined in the initial budget and/or the budget adjustment detail lines. To control extensions, four status values are available: Free Use the extension for budgeting but not for registering actual costs. Actual You can post actual costs to the extension, but it is not possible to invoice the extension. Final You are not allowed to change data. Invoicing Allowed You can post costs to the extension and you can invoice the extension. Extensions can be invoiced according to a fixed price, the budgeted contract amount or the billing amounts from the actual transactions. If it is necessary to control orders separately, you can define a start and finish date for the extension. You register the progress of an extension by extension or by extension within control code. Projects can be controlled by specific extensions or with the control budget. Extension types You can use the sessions relating to extensions to enter, display and print out changes to a project that affect customer invoicing. Four extension types are supported: fluctuation settlement provisional amount quantities-to-be-settled scope change The following types of fluctuation settlement exist: Index fluctuation settlement You can settle a percentage of the contract price according to price indices. The billable amount is based on invoiced installments or on the progress. Price fluctuation settlement You can settle items in the budget that contain a specific material (for example, copper) while accounting for possible price fluctuations of that material. Price indices are maintained at the material and data level. The invoicing is based on the progress registered in Project Progress. Invoices concerning the billing of price variations are generated. These invoices are processed by Invoicing, based on the invoicing method defined in the Project Definition module. Budget entries that contain specific materials can be settled while taking account of possible price fluctuations for those materials. Price indices are maintained by material and date. Billing is based on progress. Note You cannot define extensions of type Fluctuation Settlement for Cost Plus projects and for projects with Invoicing method set to Unit Rate. Related topics Using budgets in a project |