Innovations in production scheduling
Application of visual boards, gating, daily goals, and pull to production scheduling.

Shifting building readiness dates and product designs customized to each building and hoistway inhibit consistent and accurate production scheduling in the elevator industry. Capacity, demand, release-rate, and production policy variation inhibit throughput maximization and cycle-time predictability. Human nature and the desire to maximize revenues provide strong impetus to release work at capacity. Yet, production releases paced at or near capacity initiate a vicious cycle where production, starting from an updated near-capacity schedule, fall relentlessly behind forecast, prompting efforts to increase capacity, followed by demand reduction through ship date extensions, rescheduling, or order cancellation (Hopp & Spearman, 2001).

This paper reviews implementation of a pull-based visual scheduling system employed by The Peelle Company, a make-to-order manufacturer of freight elevator doors. The Peelle scheduling system incorporates visual management of a master production schedule with order qualification at three gate points. To decouple variable inflows of orders pushed by customers from the capacity-limited production process, the schedule system incorporates a buffer of ready-to-manufacture but not-yet-released customer orders. Production lines pull work daily from this buffer at a controlled and level pace. Daily production goals smooth production flow, facilitate interdepartmental load balancing, reduce cycle time, and maximize throughput. Kanban-based production control boards facilitate within and across departmental coordination. The result is a transparent and predictable production process conducive to changing ship dates without compromising throughput.

Prerequisites to the scheduling methodology included transition to product-family work cells, worker cross training, set-up time reduction and small lot production, standardization, outsourcing, and abandonment of practices promoting local optimization. Multiple gates during job coordination manage demand variation. Pull from a downstream production buffer mitigates capacity variation by limiting work-in-process. Daily scheduling reduces cycle-times and simplifies production control. A shift from batched to product-family production of engineering documents mitigate release-rate variation.

Managers and users report improved on-time delivery, increased customer responsiveness to ever-changing building completion schedules, greater efficiencies, and reduced fire fighting. Qualitative results suggest a more manageable system that focuses personnel on the tasks requiring completion, fosters effective coordination between upstream and downstream departments, and timely receipt of job specific materials and information. However, the scheduling system places new demands and responsibilities on line production leaders. Line production leaders find increased accountability, reduced ability to accommodate staff preferences, greater stress, and close departmental interdependencies.

The Peelle Company is a small, family owned manufacture of vertically sliding freight elevator doors. Freight-elevator doors are made/assemble-to-order and constitute part of the entire freight elevator. From standardized and conceptual designs, each freight elevator door, car gate, and car enclosure is adapted to suit customer size, hoistway space, and loading capacity requirements. For 100 years, Peelle has led this niche industry in product quality, customer service, and innovation. As a result, Peelle has maintained the industry leading position since it’s inception in 1905.

In 2000, Peelle began the lean journey. Lean implementation began with reorganization from a functional job-shop factory arrangement toward dedicated product family production lines. This process and further transformation toward mix-model production continue. Peelle instituted kanban to manage production of stock components, shadow boards, product simplification, standardization, outsourcing to relieve a key bottleneck, and visual instructions guiding factory assembly. In 2005, Peelle instituted a new visual scheduling system, which continues to evolve with introduction of a pull-based order release mechanism in early 2006. In 2007, Peelle will be incorporating two new facets into the scheduling system. The first is to initiate a daily root cause analysis triggered by failures to achieve a daily goal. Root cause analysis and solution generation will focus continuous improvement efforts and build greater acceptance of pull and lean production concepts. Secondly, Peelle plans to apply the knowledge gained from the pull based scheduling system and daily goals to other areas of the organization, such as sales and marketing.

Terry Trushinski, Lean Manufacturing Manager

Terry Trushinski is the lean manufacturing manager and organizational champion of lean at The Peelle Company, a freight elevator door manufacturer located in Brampton Ontario. During his nine years of employment, Terry Trushinski’s primary responsibilities have been developing and implementing Lean manufacturing in all aspects of the company from the office to the plant. Terry Trushinski is a graduate of Mohawk College holding a diploma in Industrial Engineering Technology –Management.

H. E. Peelle III is CEO of The Peelle Company; a small family owned manufacturing organization. Hank Peelle has worked for The Peelle Company for over 25 years, appointed CEO in 1990, and a lean advocate since 2000. Peelle holds a BS in Mechanical Engineer from Bucknell University, an MBA from UNC-Charlotte, and a Doctor of Management in Organizational Leadership from the University of Phoenix.