What is provenance?

Provenance is recorded per value, and a change gets its own source, moment and person too. In an estimate it covers every figure and requirement the cost rests on. The material may come from the title block, the price per kilo from a dated purchase price, the setup time from a manual entry and the hourly rate from the machine record. Provenance does not say whether a value is right; it tells you what to judge that against.

How does provenance work in practice?

With provenance you can trace a price back to its source: from the price to the line, from the line to its inputs, and from the inputs to the drawing, the price list or the person. That helps when two estimates for the same part disagree, for example because one used an older price per kilo or applied a tighter roughness across the whole drawing. On a repeat order, provenance lets you judge whether the old price still holds, that is, whether material price, revision and hourly rate are unchanged since the last estimate. Without a recorded source, that depends on the memory of whoever priced it.

What is provenance often confused with?

Provenance is not traceability: traceability follows the physical product, from the part back to the material heat, certificate and order; provenance follows a value in an estimate or a requirement. Nor is it the change history: that history is the series of confirmations and corrections, whereas provenance also applies to a value nobody ever changed. And it is not the inputs of a line: time, rate and quantity are the inputs, provenance says where they came from.

How do you see provenance in Blake?

In Blake an estimate line shows its inputs: time, rate and quantity. For a drawing value, who confirmed or corrected it and when stays visible, with a note if one was given; a correction to an estimate line requires a reason. Your own purchase price carries its source and date; a market reference sits beside it with a separate source and date and never counts as a purchase price. More on estimating.