Productivity gains in a line flow precast concrete process after a basic stability effort

Lean principles and methods have been successfully applied to precast concrete job shops and batch flows. The conversion of processes from batch flow environments to line flow environments is the main reason for the productivity gains that have been reported in the literature. By means of an action-research approach rooted in the philosophy of lean thinking, the authors show that further productivity gains are possible for precast concrete fabrication processes already running in line flow. This study took place at a company that had previously implemented lean measures, such as value stream mapping (VSM), workplace organization (5S Method), pull systems, and total productive maintenance (TPM). This earlier initiative provided productivity gains, although in a variable and unsustained way. The research approach could devise a simple stability process with a focus on method and manpower. After a series of improvement cycles, the production process achieved almost complete stability and obtained an additional productivity gain of 24%. These results suggest that neglecting stability issues in lean implementations means wasting part of the potential gains, in addition to risking the loss of previously obtained gains, even in environments apparently optimized for line flow.