Planning and implementing POLCA: a card-based control system for high variety or custom engineered products

Abstract

Many companies with high variety or custom engineered products are struggling to implement effective material control strategies on the shop floor, and finding that pull/Kanban systems are not meeting their needs in such environments. Paired-cell Overlapping Loops of Cards with Authorisation (POLCA) is a quick response manufacturing strategy designed with these situations in mind. POLCA is a hybrid push-pull strategy that combines the best features of card-based pull systems and push systems. At the same time POLCA gets around the limitations of pull systems in high variety or custom product environments. In partnership with its member companies, the Center for Quick Response Manufacturing (QRM) has recently implemented POLCA at several factories in the US and Canada. In this article, we first give an overview of the POLCA system, explain how it works and provide qualitative comparisons with pull/Kanban systems. Then, we present a step-wise procedure for implementing POLCA in a factory. Using examples from the implementation of POLCA at several factories, we address several practical issues such as computing the number of POLCA cards, determining the quantum of work a POLCA card represents, and addressing part shortages. We also discuss the different performance improvements that have resulted from these implementations including reductions in lead-time, increase in percentage of on-time deliveries and employee satisfaction.

Keywords:

• material control
• MRP-push
• Kanban-pull
• POLCA