Marine Electrical Power Systems:
Electric Power Load Analysis (EPLA):
Margin and Service Life Allowance

Last Update: March 6, 2026

Essential Questions

Essential Question	Level of Thinking
What is a margin and what is it used for?	Understand
What is service life allowance and what is it used for?	Understand
Who controls margin and who controls service life allowance?	Remember
How are margins and service life allowance applied in new designs?	Apply
How are margins and service life allowances applied in conversions and modified repeat designs?	Apply

DPC 310-1 Electric Power Load Analysis (EPLA) for Surface Ships

IEEE Std 45.1 IEEE Recommended Practice for Electrical Installations on Shipboard--Design

IEEE Std 45.3 IEEE Recommended Practice for Electrical Installations on Shipboard--Systems Engineering

Doerry, Norbert, "Design Criteria and Practices for the Electric Warship," presented at ASNE Advanced Machinery Technology Symposium, AMTS 2016, Villanova University Connelly Center, PA, May 25-26, 2016

Fleisher, S., and Catton, L., "Margins - their use as Metrics and Key Performance Indicators when Designing and Building Warships,” Conference Proceedings of INEC, INEC 2024, November 6, 2024, https://doi.org/10.24868/11168.

Singer, Dr. David, Dr. Jason Strickland, Dr. Norbert Doerry, Dr. Thomas McKenney, and Dr. Cliff Whitcomb, Set-Based Design , SNAME T&R 7-12 (2017)

This work by Norbert Doerry is licensed under CC BY 4.0