Jct minor works building contract 2016

Clarity please on the operation of a JCT MW contract.

The contract refers to a ‘lump sum’ – is it a lump sum with all risk on the Contractor or not?

Contractor prices quantified work schedules provided by the Employer.

Are the works remeasured to actual quantities against each work schedule upon completion or is the risk on quantities taken by the Contractor?

If quantities are remeasured, how are the increases / decreases valued ? If there are no changes to the quantities, is the item measured on n interim basis of calculated as a percentage completed, or only paid when 100% (as per an NEC Option A).

Where there are variations that do not relate to th existing work schedules, what is the primary mechanism for evaluating change?

Regards,