Engine_TOC_Workbook_Instructions_(19OCT16).docx

Patrol Boat Replacement (PB-X) Engine Total Ownership Costs (TOC) Estimator Workbook Instructions

1. Purpose The purpose of the Engine Total Ownership Cost (TOC) Estimator Workbook is to generate a reasonable estimate of the life-cycle costs associated with maintenance and fuel consumption for proposed propulsion engines for the Patrol Boat Replacement (PB-X) craft. This document will provide the builder instructions on how to navigate and properly fill out the workbook.

2. Fuel Consumption Worksheet The fuel consumption worksheet estimates the amount and cost of the fuel consumed throughout the life cycle of the PB-X. The spreadsheet calculates fuel consumption by combining user specified single engine fuel consumption for idle, patrol, cruise, and sprint operating profile speeds with mission profile percentages for two missions and yearly OPTEMPO hours across a 15 year service life. The operating profile speeds and mission profile percentages are described below. OPTEMPO hours for this worksheet are set at 2000 hours. Life cycle fuel costs are calculated by multiplying the yearly fuel consumption by the yearly projected diesel fuel costs (EIA, AEO2014) over the next 15 years.

Operating Profile Speed Definitions

· Idle – Minimum Power (in gear)

· Patrol –10 knots

· Cruise – Most fuel efficient speed above or equal to 25 knots

· Sprint – 100% Power The fuel consumption worksheet also performs fuel capacity check that compares the fuel consumption during the Harbor Patrol and HVU Escort missions over 12 hours to ensure the user specified fuel tank capacity is not exceeded. The worksheet also performs a range check based upon user specified fuel tank capacity and cruise speed to ensure the user’s proposed engines can meet the required range of 200 NM as stated in the PB-X Specifications (Section 050-1 Craft Performance Thresholds). Both the fuel capacity and range checks include a 10% fuel tank reserve per PB-X Specifications (Section 085-1 Technical Design Analyses).

2.1. User Instructions

NOTE: The user shall fill in orange cells only. The user shall not modify, remove, or add to worksheet outside of the orange cells.

The user shall fill in engine model, engine rated horsepower, fuel tank capacity, and cruise speed cells (B3:B6) at the top of the worksheet. Engine model cell shall include make and model information and may contain text and numerical values. Engine rated horsepower, fuel tank capacity, and cruise speed cells shall be numerical values only. Fuel tank capacity value shall be in gallons only. Cruise speed value shall be in knots only.

The user shall also fill in the Craft Forward Speed (C20:23) and Single Engine Fuel Consumption cells (D20:D23). These input values shall be numerical and be in knots and gallons per hour (GPH) only. Column E, “Comments”, has been provided for user comments, if needed.

OPTEMPO Hours, Service Life, Required Range, and Fuel Tank Capacity Minus 10% Reserve values in rows 9 thru 12 are PB-X Specification requirements and shall not be modified by the user.

2.2. Results

Once user’s values are filled in, the worksheet will automatically calculate fuel consumption and costs. Rows 26 thru 31 calculate fuel consumption for the Harbor Patrol mission and rows 34 thru 39 calculated fuel consumption for the HVU Escort mission. Yearly and life cycle fuel consumption is calculated and displayed for each operating profile speed. The individual fuel consumption values are then summed to give the total yearly and life cycle fuel consumption.

Total life cycle fuel costs are calculated in cells B15 and B16 for the Harbor Patrol mission and HVU Escort mission, respectively. These values are given in FY17 dollars.

The Fuel Capacity Check is provided in rows 42 thru 45. The checker displays the total gallons burned for the Harbor Patrol and HVU Escort missions over 12 hours (B44:B45) and also displays a visual verification of capacity (C44:C45). The checker will display different color-coded messages if the fuel consumption is less than tank capacity with 10% fuel reserve, within the fuel reserve, or greater than tank capacity. The Range Check is provided in rows 48 thru 50. This checker displays the total range on the builder’s proposed boat at cruise speed, assuming calm seas. The checker automatically incorporates the 10% fuel reserve in its calculations. The Range Checker also displays visual verification, via color-coded messages, of whether the boat’s calculated range meets or fails the 200 nautical mile requirement.

3. Engine Maintenance Worksheet The engine maintenance worksheet estimates the life cycle costs associate with engine maintenance labor and materials by evaluating routine engine maintenance tasks. The engine maintenance tasks in this worksheet were generated from historical maintenance documents for marine propulsion engines. The user is granted permission to add to or modify these task to suite their specific engine’s requirements.

The spreadsheet calculates the total life cycle labor hours for both engines’ maintenance items by combining the user’s estimated labor hours per task along with the user’s specified task frequency (i.e. hours between each maintenance task) over a 15 year service life at 2000 OPTEMPO hours per year. The total life cycle maintenance labor hours are then multiplied by the Maintainer labor rate to obtain the total maintenance labor cost.

The engine maintenance worksheet also estimates the life cycle maintenance material cost. The total material cost is calculated by combining the user specified cost for individual material items required to complete all the maintenance tasks with the number of times the tasks must be completed over the craft’s life cycle. Material items may include oils, rags, filters, and other consumables.

Finally, the engine maintenance worksheet estimates the life cycle engine overhaul cost. This cost is calculated by combining the user estimated full engine overhaul cost by the frequency of overhaul over the craft’s life cycle. The overhaul estimate includes both labor and material costs. This life cycle overhaul cost estimate is then combined with the life cycle maintenance labor and material costs to generate the total engine maintenance life cycle cost estimate.

3.1. User Instructions

NOTE: The user is permitted to insert new rows in the Life Cycle Labor Cost matrix and Life Cycle Material Cost matrix and modify orange cells. Apart from these allowances, the user shall not modify, remove, or add to worksheet.

The user shall fill in engine model, engine rated horsepower, overall reliability: Mean Time Between Failures (MTBF), and Mean Time To Repair (MTTR) cells (C3:C6) at the top of the worksheet. Engine model cell shall include make and model information and may contain text and numerical values. Engine rated horsepower, MTBF, and MTTR shall be numerical values only. MTBF and MTTR shall be in hours only. The user may optionally provide additional supportability analysis documentation in a separate document for the proposed engines.

The user shall fill in the Life Cycle Labor Cost Matrix. The user shall input the engine maintenance task description in Column B, “Task”. The user shall then input the corresponding labor hours required to perform the task on a single engine into Column C, “Estimated labor hours per task per engine”. This value shall be numerical only. The user shall then input the frequency of the task in hours into Column E, “Frequency”. This value shall be numerical only as well. The user shall not modify Columns D and F. Column G, “Comments”, has been provided for user comments, if needed. The user shall not modify the maintainer labor rate cell.

The user shall then fill in the Engine Overhaul Cost matrix. The user shall input the frequency of a full engine overhaul into Column C, “Frequency”. This value shall be in months and numerical only. The matrix will automatically calculate the number of times the overhaul will occur over the service life of the craft in Column D. The user shall not modify this column. The user shall also input the estimated cost for a full engine overhaul into Column E, “Cost”.

The user shall also fill in the Life Cycle Material Cost Matrix. This matrix groups all the materials required to perform the maintenance tasks from the Life Cycle Labor Cost matrix under the specific task. The user can expand each task by clicking on the “+” button on the left side of the worksheet. The user shall list all items required to perform the maintenance task along with part numbers, quantity, unit of issue, and unit costs in columns C thru G of the matrix. Columns H thru J will calculate the total item costs per task for the life cycle of the craft. The user shall not modify these columns. Column K, “Comments”, is provided for user comments and maybe filled in by user as needed. The user is allowed to add additional rows to the Life Cycle Material Cost Matrix as required.

3.2. Results

Once all the data has been filled in by the user, the worksheet will calculate the total engine maintenance life cycle cost.

First, the worksheet calculates the total life cycle labor cost using the Life Cycle Labor Cost matrix. Column F, “# times/service life”, automatically calculates the number of times each maintenance task will be accomplished over the service life of the craft using the user specified frequency and the PB-X Specification stated OPTEMPO hours and service life. Column D, “Life Cycle labor hours per task/twin engine”, automatically calculates the total life cycle labor hours required to complete each maintenance task for two engines by combining the user specified labor hours and frequency. The Life Cycle Labor Cost Matrix then calculates the total life cycle maintenance labor hours and total life cycle maintenance labor cost using user specified labor hours and a Government specified labor rate.

Second, the worksheet calculates the total life cycle overhaul cost by combining the number of engine overhaul occurrences for each engine with the cost for each engine overhaul.

Third, the worksheet calculates the total life cycle material costs. The Life Cycle Material Cost Matrix calculates the total item costs for each maintenance item in Column H, “Total Item Cost”, and combines them with the number of occurrences of each maintenance item in Column I, “# times/service life”, as defined in the Life Cycle Labor Cost Matrix, to produce a total maintenance task life cycle material cost (Column J). The matrix then adds all the total maintenance task life cycle material costs to generate the total life cycle material costs.

Finally, the Engine Maintenance Worksheet combines the total life cycle labor cost, overhaul cost, and material cost to generate the Total Engine Maintenance Life Cycle Cost. This value is reported in Cell C14.