Maintain operational efficiency by implementing drum buffer rope system in the planning stage
The drum buffer rope system is a management concept where the drum is the slowest person in a group but the rope that binds the group cannot go faster than the slowest person, and a buffer has some degree of independent movement. It is important to note that the drum buffer rope system refers more to processes than individual people in an organization.
The origin of the drum buffer rope system goes back to the concepts created by Eliyahu Goldratt in his book named ”The Goal”. This book also mentions different methods to manage production systems. These processes are today known as Kanban or CONWIP with a little Japanese management fine-tuning.
The Eliyahu Goldratt concept centred around a management system and romance novel combination. Another contemporary with a similar management romance combination was Freddy and Michael Balle in their novel “The Goldmine: A Novel of Lean Turnaround”.
The Goal featured a story about a slow boy in a boy scout group on an excursion. In order to prevent slower boys from lagging behind and getting lost, the slowest boys were put in front of a walking line in order to ensure nobody else could overtake this slower boy. Hence, the speed of this boy became the speed of the group and was the drum, the bottleneck.
This concept is similar to a kanban system where the bottleneck is identified, and planning is always done in a way so as to prevent overloading of the system. The drum or the bottleneck identified the CONWIP concept looks for ways to increase the efficiency or speed of the bottleneck. This is similar to the boy scout story where the backpack of the slow boy leading the group was lightened in order to increase his speed and consequently the speed of the whole group.
The Drum barrel rope model extended to placing a buffer in front of the drum or bottleneck as a signal to replenish material. Still, it had no control over the downstream process. The drawback in this system was that it did not focus attention on downstream processes and was not effective in preventing overproduction and creating a lean and efficient system. Although this system was an early forerunner of the theory of constraints, followers of the Drum buffer rope system recognized the flaw in the early model and modified the system by introducing an additional buffer after the drum to prevent inconsistencies in downstream material flow, the Kanbahn system with its greater control of every step of the process began to find wide acceptance.
The Drum barrel rope system has its benefits as well, due to which it is increasingly popular, and this is because it measures in real-time as compared to the number of pieces in a kanban system. This system also measures the work in the system. The Drum barrel rope system is effective for planning and can maintain operational efficiency by identifying bottlenecks, providing means to lighten the bottlenecks and also ensure maximum utilization by effectively utilizing all WIP (work in process) just enough to prevent overloading at any stage.
Effective planning can take into account shifting bottlenecks instead of the fixed bottlenecks in the original Drum buffer rope model. Efficient planners can identify potential and dynamic bottlenecks, provide them in real-time, and plan production schedules more effectively. Planners have the flexibility to implement the best of the Drum barrel rope, Kanban and CONWIP processes and simply eliminate the processes that inhibit operational efficiency.
The Drum buffer rope model effectively enhances operational efficiency at the planning stage for manufacturing systems.
