MRPII-JIT-TQM Integration
Part 4 of 6

 The Lean manufacturing, PPT Plus,
"Back-to-Basics" Training Library 
Lean Manufacturing Education

Increase the effectiveness of your
Lean Manufacturing Training Program
Lean Manufacturing Simulation Game 

Kanban Planning System

Figure 4, MRP-Driven Pull System applicable to the hybrid environment dynamically identifies JIT pull items and unique items for a given demand mix and this information is used to update the Kanban parts and inventory. In the repetitive environment all parts are treated as Kanban parts. The underlying principle behind the planning sys­tem is that the basic database structure must resemble the JIT material flow and manufacturing processes performed on these materials. In tune with this principle the bills of materials in the repetitive environment are practically flattened with the use of phantoms. In case of the hybrid environment the intermediate level subassemblies are identified as either Kanban or unique items. An operation sequence is attached to each component in a bill where it is consumed on the routing. This approach provides the flexibility for a time phased implementation of the JIT layout changes while making minimum changes to the product database.

The bottom level components, usually purchased or fabri­cated parts with repetitive usage are selected as Kanban parts. The intermediate level major subassemblies with repetitive usage and short lead times are selected for Kanban subassemblies to be run by Kanban work orders. All Kanban items are planned and stocked at the consuming work cells using a two bin system. All unique items are stocked in the stores and kitted when required for work orders.

Scheduling Systems

The end item build schedules satisfying a given product mix and customer requirements drive the MRP II system. The MRP-driven scheduling system provides a weekly net rate production schedules for each work cell and schedule priorities for the Kanban and unique work orders. The MRP-driven scheduling system also provides weekly sched­ules and release rates for purchase parts and release rates for manufactured items with mixed models.

Execution/JIT Material Flow

The execution systems in the factory consist of the final assembly releases and unique work order releases from the MRP I system and the JIT pull system initiated from the work cell or assembly line. The unique work orders sug­gested by MRP I in the hybrid environment are processed in a similar method as traditional work orders except for the fact that only the unique components are kitted and transferred from stores to line where they are consumed as an operation sequence is moved. A Kanban work order is initiated on the shop floor when a using cell consumes repetitive subassemblies from a bin. The Kanban work order quantities are usually based upon small lot produc­tion. The supplying cell manufactures the small lot work order and replenishes the Kanban bin in the using cell. As low level Kanban parts are consumed by the line, they are replenished from the stores based upon the JIT pull sys­tem. With this approach the multilevel bill of materials is replaced by fewer level bills and the voluminous multilevel stocking, kitting and issuing activities are eliminated for the repetitive assemblies while the stocking, kitting and issuing activities are continued on a limited basis only for the unique components. The work order processing steps are however simplified or combined to minimize the manual steps.

The vendor purchases are made using the MRP I system through the blanket purchase orders or discrete purchase orders as the case may be. All purchased parts are received to stores in the case of hybrid manufacturing while in the case of repetitive manufacturing they are received either to stores or to the line directly. Kanban parts are packaged into Kanban quantities and stocked until pulled by the line.

Control Systems

The control systems consist of multistores inventory con­trol, stores and Kanban cycle counts, sales order tracking, input and output production tracking, production comple­tions reporting integrated with backflush system and performance measurement systems. The repetitive envi­ronment primarily may use a wall to wall inventory system while the hybrid environment uses a multi inventory system primarily with two types of inventory, one located at the main stores and the other at individual work cells.

Integrating TQM Infrastructure with MRP II/JIT

The key initiatives that create the TQM infrastructure for MRP II/JIT to successfully operate and satisfy customer requirements in both environments consist of total em­ployee involvement, teams trained on problem solving and quality improvement process, trained and certified work­ers and each focus factory operation managed by cross-functional teams and work cell teams empowered to man­age their own processes and schedules.

To be Continued