DSM-Based Quantitative Comparison of Centralized and Modular Architectures of a Field-Deployed Electrohydraulic Lifting Device, Validated by Prototype Experiments

Steel storage tanks are erected on site by multi-cylinder hydraulic lifting, conventionally from one power unit feeding all cylinders through a flow divider. Decentralized alternatives have not been evaluated for this task, and modularity in fluid power is rarely quantified. A ten-cylinder device was analyzed as a centralized (C1) and a modular (C3) variant with a servomotor-driven pump at each cylinder; both were decomposed into five functional modules and compared through a directed design structure matrix (DSM). External dependencies per module fell by 38.6% and mean interface complexity by 30.9%, against only 11.1% for interfaces per module: interfaces were thinned, not removed. Internal cohesion rose from 0.583 to 0.805; the total risk priority number, an ordinal expert-assigned indicator, fell from 2253 to 760. C1 was characterized from documentation and was not tested experimentally; a three-module prototype at a length scale of 0.31 was run through sixteen series: open and closed loop, both directions, four disturbance configurations. In open loop, the error left the ±2% band in every series; in closed loop, it stayed inside the band in lifting and over the last 91–92% of stroke in lowering, cutting the drift rate by one to two orders of magnitude. The structural gain corresponds to removing the hydraulic installation and the flow divider, which dominate both the open-loop drift and the failure-mode ranking; the modular device costs about 58% more.