Pro-rata pricing 按比例定价

With respect to the valuation of variations refers to taking into account similarity, character, conditions and quantity of work involved and this can be problematic at times.

工程變更是指考慮到所涉及的工作的相似性，性質，條件和數量。

Where no direct price is available at rates that are based on the bill rates, this is known technique called “Pro rata pricing".

如果沒有相似的直接價格，就會用稱為按比例計算的技巧。

When attempting a pro rata calculation, a known built-up rate is broken down into its constituent parts so that it can be adjusted. If too many of the elements that constitute a rate have to be adjusted then it is better.

在嘗試按比例計算時，將已知的價格分解為其多個組成部分，以便可以對其進行調整。如果必須調整組成部分越多，那麼會更好。

As the contractor is present it may be possible to refer back to the original price build-up and this will make the process easier.

Generally, the Bill rates are composed from the following:

1. Labour勞工

2. Material材料

3. Plant and equipment工廠和設備

4. Profit and overheads利潤及管理費用。

The technique involves disassembling a bill rate and substituting new data in order to calculate a new rate for pricing variations.

該技術涉及拆解價格並替換新數據以計算變化的新價格。

The approach is to analyse the original bill rate as follows:

1. deduct profit and overheads,

2. analyse materials, labour and plant costs,

3. adapt costs (labour/material/plant and equipment) to suit new item, and

4. add back profit and overheads.