Acquisition Cost Estimating

Required Inputs

The method used for estimating the Acquisition costs in the spreadsheet requires the following inputs;

Base Year
Total Installed Brake Power
Approximate Fuel Rate
The Single Digit SWBS Weight Breakdown for the Vessel, including;
- Design & Build Margins
- An Estimate of the Gyro, Internal Communications and Navigation Weights of the Vessel (SWBS 420 & 430)
- Mission Related Expendables (WF20)
Profit
A Change Order Factor (for both the Lead Ship and any Follow Ships)
Other Support Cost Factor (for both Lead Ship and any Follow ships)
A Program Management (PM) Growth Factor (for both Lead Ship and any Follow ships)
An Ordnance & Electronics Government Furnished Equipment (GFE) Estimate (for both Lead Ship and any Follow ships)
A Hull, Mechanical & Electrical (HM&E) for Boats and Interior Communications GFE Factor (for both Lead Ship and any Follow ships)
An Outfitting Cost Factor (for both Lead Ship and any Follow ships)
A Post Delivery Availability (PSA) Cost Factor (for both Lead Ship and any Follow ships)

Here;

Base Year is the year that the ship is to be laid down.

Total Installed Brake Power as defined in the Power Estimation Section of the Spreadsheet.

Approximate Fuel Rate is measured in tons/hr. Currently I do not have a method to calculate this yet, but I am currently working on incorporating something soon. The Single Digit SWBS Weight Breakdown for the Vessel which will include the w100, w200, w300, w400, w500, w600, w700 weights and the Design & Build Margins (M24), and an Estimate of the Gyro, Internal Communications and Navigation Weights of the Vessel (SWBS 420 & 430) and Mission Related Expendables (WF20). For the SWBS 420 and 430 value, the spreadsheet currently does not calculate this, but based on some limited data from design studies for similar ships a default value of approximately 26% of the Total w400 weight appears to be a usable estimate for now, and is recommended as a default value for now. Additionally, the Mission Related Expendables (WF20) weight is also not currently estimated in the spreadsheet and as such, currently a default value of "0" is used.

Profit assumed to be a % of the Total Ship construction Cost, and the theses that the Acquisition Costs have been based on suggest a default value of 15% here.

The Change Order Factor (for both the Lead Ship and any Follow Ships) is assumed to be a % of the Ship Price and a value of 12% for the Lead Ship and 8% for Follow Ships is currently recommended in the Reference Theses as default values.

The Other Support Cost Factor (for both Lead Ship and any Follow ships) is also assumed to be a % of the Ship Price and a value of 2% is currently recommended for both the Lead Ship and any Follow Ships as default values.

A Program Management (PM) Growth Factor (for both Lead Ship and any Follow ships) is also assumed to be a % of the Ship Price and a value of 10% is currently recommended for both the Lead Ship and any Follow Ships as default values.

An Ordnance & Electronics Government Furnished Equipment (GFE) Estimate (for both Lead Ship and any Follow ships) is provided in terms of $M in FY81 dollars. The reference spreadsheets have suggested a default value of $373M for the Lead Ship and $326M for any Follow On ships. however, it should be noted that these values appear to have been selected as default values for general surface combatant type vessels and I am currently looking toward modifying and updating this section in the future.

A Hull, Mechanical & Electrical (HM&E) for Boats and Interior Communications GFE Factor (for both Lead Ship and any Follow ships) is assumed to be a % of the Ship Price and a value of 3% is currently recommended for both the Lead Ship and any Follow Ships as default values.

An Outfitting Cost Factor (for both Lead Ship and any Follow ships) is also assumed to be a % of the Ship Price and a value of 4% is currently recommended for both the Lead Ship and any Follow Ships as default values.

A Post Delivery Availability (PSA) Cost Factor (for both Lead Ship and any Follow ships) is also assumed to be a % of the Ship Price and a value of 5% is currently recommended for both the Lead Ship and any Follow Ships as default values.

Construction Cost Methodology

The base methodology used on estimating the Construction costs is based on information provided in the three reference theses. The specific method used is similar to the methods used by the US Navy for their ASSET Ship Synthesis computer program and MIT in the Ship Design courses (and is sometimes referred to as the MIT13A Method).

It is based primarily on associating a series of Cost Estimating Relationships (CERs) to the Single Digit SWBS weight breakdown for the ship, with the exception being that the CER for the Main Propulsion Plant (SWBS 200) is based on the total installed propulsion power of the vessel and the machinery type, rather then the SWBS 200 weight. In this method both Labor and Material Costs are lumped into a single CER for each SWBS Group.

To account for the costs associated with the Design & Build Margin, the M24 weight is distributed over the SWBS Groups weighted by the percent of total Light Ship Weight each SWBS Group accounts for. Here the base construction costs are estimated by the following general equation;

Cost = esc * f * KNi * Parameter ^ Exp

Where;

esc is the cost escalation factor to increase the cost from an Fiscal Year (FY) 1981 value to the correct Base Year for the vessel
f is a multiplier factor for each SWBS Group as defined in the Table below
KNi is a coefficient that may vary for each SWBS Group depending various specifics of the design. Because the methods discussed in the reference theses appear to have primarily been focused more toward surface combatant and patrol type vessels and because there was sometimes a range of different values suggested for KNi depending on various criteria, I have tried to include all the suggested values in the table below, but have highlighted those values that appear as being most appropriate for aircraft carrier type vessels.
Parameter is the total weight for each given SWBS Group, except for SWBS 200 where the total installed power is used instead
Exp is the value of an exponent which adjusts the shape of the cost curve for that group, and is summarized in the Table below

SWBS Group	f	Parameter	Exp
w100	0.03395	w100 Wt	0.772
w200	0.00186	Installed Power	0.808
w300	0.07505	w300 Wt	0.910
w400	0.10857	w400 Wt	0.617
w500	0.09487	w500Wt	0.782
w600	0.09859	w600 Wt	0.784
w700	0.00838	w700 Wt	0.987

Recommended KNi Values

For SWBS 100 a range of default values are suggested depending on specifics of the Design, as shown in the Table below, or the user has the option of entering his/her own desired input.

SWBS 100 Specifics Superstructure Matl/Hull Matl	KN₁₀₀	Source/General Ship Types
General	0.946	MIT 13A Recommendation
AL / MS + HTS	1.721	FFs, FFGs, MCMs
AL/ST	1.800
HTS+FRP/HTS	2.000
OS/OS	2.050
HSS/HSS	2.150
AL / MS + 25% HY80	2.702	DDGs, DLGs, DLGNs
AL / AL	3.770	CPIC, PGs
AL / HT AL	9.613	PGHs, PCHs, SESs

The figure below shows the variation in costs for each of these KN₁₀₀ values over a range of typical w100 weights.

For SWBS 200 a range of default values are suggested depending on specifics of the Design, as shown in the Table below, or the user has the option of entering his/her own desired input.

SWBS 200 Specifics	KN₂₀₀	Source/General Ship Types
High Speed CODOG/CODAG	1.721	CPIC, PGs
General	2.065	MIT 13A Recommendation
GT/CODAG w/Rt Angle Drive	2.585	PCHs, PGHs, SESs
Diesel	2.600
CODOG	2.750
CODAG	2.900
COGAG	3.200
Steam & CPP	3.406	DDGs, DLGs
GT (including SWATH)	4.035	FFGs, SWATHs
GT w/ Comlex Drives	5.644	LCAC, JEFF(A)
Nuclear	5.913	DLGNs

The figure below shows the variation in costs for each of these KN₂₀₀ values over a range of typical Installed Power values.

For SWBS 300 a range of default values are suggested depending on specifics of the Design, as shown in the Table below, or the user has the option of entering his/her own desired input.

SWBS 300 Specifics	KN₃₀₀	Source/General Ship Types
Conventional Steam or Diesel	1.721	FFs, DDGs, DLGs, PGs, DLGNs, SWATHs
Conventional Lt Diesel or GT Gen	3.504	PCHs, PGHs, SESs
Very Low 60Hz or 60/400 Hz GT Drive	6.400	(SESs, SWATHs)
All 400 Hz GT Drive	21.827	PHMs, JEFF(B)

The figure below shows the variation in costs for each of these KN₃₀₀ values over a range of typical w300 weights.

For SWBS 400 a range of default values are suggested depending on specifics of the Design, as shown in the Table below, or the user has the option of entering his/her own desired input.

SWBS 400 Specifics	KN₄₀₀	Source/General Ship Types
Simple w/Minimal Electronics	1.721	CPIC, PGs, FFs, DLGs
General	3.442	MIT 13A Recommendation
Modest w/Sophisticated Electronics	5.426	FFGs, DLGNs, SWATHs
General	6.000	From Reference Data
Complex w/Soph Elect (Wt Crit Des)	11.884	PCHs, PGHs, JEFF(A&B)

The figure below shows the variation in costs for each of these KN₄₀₀ values over a range of typical w400 weights.

For SWBS 500 a range of default values are suggested depending on specifics of the Design, as shown in the Table below, or the user has the option of entering his/her own desired input.

SWBS 500 Specifics	KN₅₀₀	Source/General Ship Types
Steam Propelled Displacement Ship	1.721	FFs, DLGs
General	2.250	From Reference Data
General	2.581	MIT 13A Recommendation
GT Propelled Displacement Ship	2.629	CPIC, PGs, FFGs, DLGNs, SWATH
Fully Submerged Hydrofoils	7.160	PCHs
ACVs & SESs	9.241	ACVs, SESs

The figure below shows the variation in costs for each of these KN₅₀₀ values over a range of typical w500 weights.

For SWBS 600 a range of default values are suggested depending on specifics of the Design, as shown in the Table below, or the user has the option of entering his/her own desired input.

SWBS 600 Specifics	KN₆₀₀	Source/General Ship Types
Conventional Displacement	1.721	CPIC, PGs, FFs, FFGs, DLGs, DLGNs
Weight Critical Ship	3.196	PGHs, PCHs, SESs

The figure below shows the variation in costs for each of these KN₆₀₀ values over a range of typical w600 weights.

For SWBS 700 a range of default values are suggested depending on specifics of the Design, as shown in the Table below, or the user has the option of entering his/her own desired input.

SWBS 700 Specifics	KN₇₀₀	Source/General Ship Types
General	1.300	From Reference Data
Conventional Displacement	1.721	CPIC, PGs, FFs, FFGs, DLGs, DLGNs
General	2.289	MIT 13A Recommendation
Weight Critical Ship w/ Light Armament	5.853	PGHs, PCHs, SESs, SWATHs

The figure below shows the variation in costs for each of these KN₇₀₀ values over a range of typical w700 weights.

In addition to the SWBS 100 to 700 weights, there are also costs associated with Shipyard Technical Support (SWBS 800) and Shipyard Support Services (SWBS 900). The costs for these groups follow the same equation as the other SWBS Groups, where the Parameter is the sum of the margined w100 to w700 costs and;

f for Group 800 may be on the order of 0.034 to 0.037 for the Lead Ship, based on data in the reference theses, with a value of 0.037 recommended as a default value. For a Follow On Ship a value between 0.019 to 0.104 being suggested, with the value of 0.019 being recommended as a default value.

KN₈₀₀ for the Lead Ship ranges over the following values;

Lead Ship Characterization	KN₈₀₀	Source/General Ship Types
General	8.500	From Reference Data
General	10.000	MIT 13A Recommendation
w/ Unsophisticated Weapons	12.888	CPIC, LCACs, MCMs
w/ Sophisticated Weapons	26.064	FFGs

For Follow On ships a value of KN₈₀₀ = 1.000 is recommended for ships built before 1970, or KN₈₀₀ = 2.881 for ships built after 1970.

f for Group 900 is recommended as 0.135.

KN₉₀₀ may range over the following range of values;

Ship Characterization	KN₉₀₀	Source/General Ship Types
Simple Tooling & Limited Trials	1.000	CPIC, PGs, FFs, DDGs, DLGs
General	1.800	From Reference Data
General	2.000	MIT 13A Recommendation
Complex Tooling & Extensive Trials	4.254	SWATHs, PHMs, SESs, ACVs, FFGs, DLGNs

The figures below shows how all the various components of Acquisition Costs add together.