Question

For preliminary estimates, the ratio of indirect costs to direct costs for chemical plants is often in the range

• A. \(0.1-0.3\)
• B. \(0.3-0.5\)
• C. \(0.5-0.8\)
• D. \(1.0-1.5\)

Hint:

Remember that \(\text{FCI} = \text{Direct Costs} + \text{Indirect Costs}\). For a standard preliminary estimate, indirect costs are roughly a bit over half of the direct costs, falling into the \(0.5 - 0.8\) range.

Answer 1

The Correct Option is C

Concept: When estimating the Fixed Capital Investment (FCI) of a process plant, expenditures are categorized into direct and indirect costs:
• Direct Costs: Material and labor expenses directly involved in constructing the physical facilities (e.g., equipment purchase, piping installation, electrical work, instrumentation, land, civil foundations).
• Indirect Costs: Expenses required to support construction that do not become part of the final physical structure (e.g., engineering design fees, supervisory expenses, construction tools, contractor fees, legal expenses, contingencies).

Step 1: Evaluating the ratio of indirect to direct costs.
For standard fluid-processing chemical plants, indirect costs are significant due to the extensive engineering design, project management, and safety contingencies required. Empirical data from project accounting shows that indirect costs typically range from \(50\%\) to \(80\%\) of the direct costs. This gives a ratio of: \[ \text{Ratio} = \frac{\text{Indirect Costs}}{\text{Direct Costs}} \approx 0.5 - 0.8 \] This historical range matches option (3).