result in multiple forms of waste and increased cost as described above. Thus, QRM encourages enterprise to strive towards batch sizes that minimize lead times. Enterprisewide Application QRM emphasizes time-based thinking throughout the organization, creating a unified management strategy for the entire enterprise. Extending beyond traditional efforts to optimize shop floor operations, QRM applies time-based management principles to all other parts of the organization. Office Operations QRM identifies office operations such as quoting, engineering, scheduling and order processing as major contributors to lead times. To achieve short lead times in the office environment, QRM suggests implementing several changes according to the time-based approach described above. The main requirement for reorganizing office operations in QRM is the formation of a Quick Response Office Cell (Q-ROC) around a Focus Target Market Segment (FTMS). In their focus on closed-loop, collocated, multifunctional, cross-trained teams, Q-ROCs are similar to QRM Cells. Q-ROCs, like QRM cells on the shop floor, break down functional departments and can complete jobs through multiple functional steps. Material Planning QRM criticizes commonly used material planning and scheduling systems such as Material Requirements Planning (MRP), Manufacturing resource planning (MRP II), and Enterprise resource planning (ERP) for not incorporating system dynamics in their analysis and not accounting for the cost of long lead times. QRM recommends simplifying existing MRP systems to a Higher Level MRP (HL/MRP) concerned with high-level planning and coordination of material and not with detailed scheduling of operations. Production Control To coordinate and control flow within the QRM structure of cells and HL/MRP, QRM utilizes POLCA (Paired-cell Overlapping Loops of Cards with Authorization). POLCA is a card-based shop floor control system, designed as the QRM alternative to Kanban. POLCA differs from commonly used Kanban systems in the type of signal it sends to move jobs/material through the shop floor. POLCA constitutes a capacity signal, showing that a cell is ready to work on a new job, whereas Kanban systems rely on inventory signals designed to replenish a certain quantity of parts. For this reason, POLCA works well for low-volume and/or custom products. The first QRM shop floor control system was developed by PROPOS software. PROPOS software was also the first to develop a digital version of the POLCA card system. In March 2018 Rajan Suri published The Practitioner's Guide to POLCA: The Production Control System for High-Mix, Low-Volume and Custom Products] in which Suri describes a practical approach to POLCA