Detailed Unit Cost Metrics

Like the summary cost metrics, the objective of the Detailed and Unit Cost Metrics is to support estimate development and review. However, these metrics provide many more levels of detail in the metrics, from discipline-level cost ratios (e.g., Piping Engineering Cost / Piping Construction Cost) to labor rates to unit hours (e.g., Piping Labor Hours / Piping Feet). These metrics are used in early estimate development to provide factors for material and labor disciplines and for bottoms-up estimate validation for more defined estimates (e.g., Class 3). The following is a brief description of the sets of metrics in this report:

• Level 1: Ratios of summary cost account subtotals to total project cost and similar metrics (compare these metrics to the Summary Cost Metrics Report). Useful for proportional cost checks (e.g., engineering cost to total cost).
• Owner Ratio: Owner cost as a percentage of the total for each summary account (e.g., owner costs are X percent of the total project management costs). By definition, contractor costs are equal to 100 minus the owner percentage.
• Discipline Ratio: The ratio of the total cost of each discipline and trade to their respective office and field sub-totals and to the total project cost (e.g., mechanical engineering as a fraction of total engineering and of the total project).
• Discipline Ratio for Construction Labor: The ratio of the labor cost of each construction trade (including indirect accounts) to the total construction labor cost (e.g., piping labor cost as a fraction of the total construction labor cost). It is useful for proportional checks of the construction disciplines.
• Labor/Material Ratio: The ratio of the labor cost to the materials cost for each construction trade (e.g., piping labor cost/piping materials cost). It is useful in developing conceptual estimates to validate the labor factors.
• Engineering/Construction Ratio: The ratio of the cost of each engineering discipline to the cost of its respective construction trade (e.g., piping engineering/construction piping). It is useful in developing conceptual-level estimates to validate the material factors.
• Engineering Hours/Material Quantities (i.e., engineering productivity): The engineering hours per unit of material quantity associated with that engineering discipline (e.g., piping engineering hours per linear foot of pipe). It is useful in the bottoms-up validation of the engineering discipline accounts.
• Labor Rates: The cost per hour in 2015 dollars for each office and field discipline or craft (where there is a significant difference); it covers both the owner and contractor (e.g., piping dollars/hour).
• Material $/Equipment $: The ratio of construction material cost to equipment cost for each construction trade (e.g., piping material cost/equipment cost). It is useful in developing conceptual-level estimates to validate material factors.
• Hours/Material $: The construction hours per hundred dollars of material (in 2015 dollars) for each construction trade (e.g., piping hours per hundred dollars of piping material). It is useful in validating the construction discipline accounts in the absence of material quantities.
• Unit Hours (i.e., construction productivity): The construction hours per unit of material quantity for each construction trade (e.g., piping hours per linear foot of pipe). They are useful in the bottoms-up validation of the construction discipline accounts.
• Unit Material $: The construction material cost in 2015 dollars per unit of material quantity for each construction trade (e.g., piping material cost per linear foot of pipe).
• Unit Total $: The construction total cost in 2015 dollars per unit of material quantity for each construction trade (e.g., total piping cost per linear foot of pipe). It is useful in validating the discipline-level accounts for unit rate contracts.
• Material Quantity Ratios: The ratio of one material quantity to another (e.g., feet of piping per piece of equipment or ton of steel per foot of pipe). It is useful in validating the material quantities required to support the major process equipment.
• General Hour Ratios: The overall office and field hour, project management hour, and construction management hour metrics. They are useful for high-level checks of the PM, Engineering, and Construction hours.