Drum Buffer Rope Case Study

By Dr Lisa Lang

The rock stars at Cavaform International LLC proved that Velocity Scheduling System based on Goldratt’s Theory of Constraints and Drum Buffer Rope WORKS!  After just 2 months Cavaform experienced a 2.6 X improvement in pieces shipped.  

Cavaform International LLC Doubles Output in less than 2 months

I received another update at the end of April showing the results continued.  The units shipped went down by a few units but this was due to working fewer hours.  But their productivity/efficiency actually continued to improve. 

Cavaform Doubles Productivity with Velocity Scheduling System

So Cavaform has successfully uncovered capacity allowing them to substantially improve their due date performance.  From the data you can see that they did cut the time through their shop by more than half.  I haven’t asked them about the 3rd promise of VSS, chaos reduction, but I suspect that has also reduced.  I mean, they had time to send me this data.  

Cavaform International concentrates on close tolerance injection molds and mold components for the plastics industry. Cavaform builds molds for the medical, lab disposables, home and personal care, packaging, writing instruments and cosmetic markets. Cavaform also specializes in Catheter tipping tool dies where ultra precision and high polish is required! 

 So if you need a new tool or a replacement, why would you go to the vendor that’s going to over promise and UNDER deliver when you could go to Cavaform?  Seems to me that Cavaform is the clear choice.

And Cavaform has also proved another thing I preach — that efficiency is an effect and NOT a prerequisite to improved performance.

Have you done the math?  What their ROI might be on the Velocity Scheduling System Coaching Program?  What would yours be if you doubled your output?

So what are YOU waiting for?  Think you’re s00o different this won’t work for you?  Maybe (and you can evoke the guarantee), but what if it does work for you?  Check out the FAQs and then if you still have questions, drop me line, pick up the phone, leave a question in the comment box, but don’t just wonder.

Share and Enjoy:

Tagged as: Cavaform, Drum Buffer Rope, Goldratt, Theory of Constraints, theory of constraints case study, theory of constraints drum buffer rope, theory of constraints results, theory of constraints testimonials, Velocity Scheduling System

Lean Manufacturing - The ThermoFab Advantage

As a lean manufacturing organization, working with ThermoFab offers advantages in material handling, inventory, quality, flexibility, scheduling, personnel and, ultimately, in your satisfaction.

Our entire process is centered on ensuring you receive high quality products on-time. ThermoFab has seen significant benefits from applying the principles of the Theory of Constraints (TOC) and implementing VISUAL DBR (Drum-Buffer-Rope) through our work with Synergy Resources.

ThermoFab follows the Theory of Constraints (TOC) business management philosophy called Drum-Buffer-Rope (DBR), which was developed by Dr. Eli Goldratt, author of The Goal: It’s Not Luck, Critical Chain, and Necessary But Not Sufficient.

DBR controls the flow of materials through the plant so that products are produced according to market demand with a minimum of manufacturing lead-time, inventory and operating expenses.

Drum, Buffer, Rope Definitions

Drum – Constraints or bottlenecks in the process. This is what is being managed to ensure a smooth flow.

Buffer - A protection against Murphy. This is the time provided for parts to reach the protected area. The protected areas are the Drum, the due dates and the assemblies of constraint parts with non-constraint parts.

Rope - A schedule for releasing raw materials to the floor. The Rope is derived according to the Drum and Buffers; its mission is to ensure the proper subordination of the non-constraints.


The DBR technique enables companies to maximize a Capacity Constraint Resource and use time buffers to create schedules that help deliver products on time. Drum-Buffer-Rope is based on the TOC logistics approach and its five steps of focusing:

  1. Identify the System's Constraint(s).
  2. Decide How to Exploit the System’s Constraint(s).
  3. Subordinate Everything Else to the Above Decisions.
  4. Elevate the System's Constraint(s).
  5. If, in the Previous Steps, a Constraint Has Been Broken, Go Back to Step One,
    but Do Not Allow Inertia to Cause a System's Constraint.
Our lean manufacturing system provides you with the greatest flexibility of any manufacturer. ThermoFab will work with you to create a yearly blanket order with monthly releases based on a 45-day rolling forecast. This push-pull system with a 45-day window for planning deliveries offers you extensive flexibility - allowing for market changes and growth within your product lines.

To learn more about how ThermoFab's investment in lean proccesses helps us provide you with Manufacturing At Warp Speedcontact us by email or call 888-494-9777.

Send us your CAD files today or contact us for a project assessment.

0 Replies to “Drum Buffer Rope Case Study”

Lascia un Commento

L'indirizzo email non verrà pubblicato. I campi obbligatori sono contrassegnati *