The analysis of military shipbuilding approach evolution from Eighties to today has been carried out. From the Italian Navy point of view the comparison between the Italian DDGs “Admirals class” and the “Horizon class” showed how much technological development and information technology have provided the crew reduction as main result. This interesting trend is common, as well as the Italian Navy, in all NATO navies; therefore wondering whether or not a minimum manning level exists so that it is not feasible further reducing number of the Scheme of complement (SOC) is more than shared. Moreover, as manning reduction studies are usually an industrial task included within the main shipbuilding program, they have so far showed their limits, like:

• Commercial design influence;
• Main target has always been to demonstrate validity of the SOC assumed as an input of the study.
• the industry’s recommendations for SOC reduction are sometimes in contrast with current internal doctrine and regulations regarding the management of personnel on board.

All that said, with the aim to have SOC assumption during the preliminary phases of the naval design as close as possible to the final one, the author has developed a tool based on:

• Missions and Scenario the ship will be called to face;
• On board Combat System equipment and operational tasks;
• Contemporaneity of tasks and their interactions with automation system;
• Platform System equipment;
• Policy of manning reduction (look-out man, helmsman vs autopilot, CCTV vs  man in engine room etc ...).

The outputs, i.e. the preliminary SOC, have been validated through the lessons learned coming from naval training performed by existing vessels and therefore in line with Italian Navy regulation and it could be a good starting point in the feasibility studies in assuming relevant SOC to be used as a reference for general arrangement and equipment sizing in line with internal naval policy and procedures.