If you want to assess the volume of agricultural produce, use the guidance available in the Reported Agricultural Output indicator.
If you know that you will need to measure the volume of non-agricultural production, first assess whether the target producers have a reliable system of systematically recording the amount of the products you are interested in (including whether they are able to report on the period you are interested in alone). If such a system is not in place (or is not likely to be reliable), discuss with the producers the possibility of them keeping regular records and supporting them in doing so.
