EPCM contractors preferred to present capex cost estimates one way but Clients preferred it another way.
EPCM contractors preferred to present capex cost estimates using a % confidence (z in the above image)
Capex approvers preferred a simple +/- or not to exceed.
I found myself as project manager taking responsibility for transposing one into the other. This involved interpreting the EPCM’s probability curve which had its risks but was needed for stakeholder management
It was essential to fully understand the EPCM contractor’s estimating methodology and the Client’s expectation to ensure this task did not add risk to the project