Theory of Constraints
The Theory of Constraints and Drum–Buffer–Rope
Drum – Buffer – Rope (DBR) is an operations scheduling methodology based on Dr Eli Goldratt’s Theory of Constraints (TOC) and first written about in The Goal and further explained in The Race. Drum Buffer Rope is just one part of the TOC Operations solution; it is the machine that sets the plan for Operations. However the second part of the TOC Operations solution is Buffer Management. Buffer Management is the monitor and control mechanism that ensures the machine is running well in execution.
Theory of Constraints takes a systemic view of a company or organisation. This means it treats the organisation as one and not as a number of different departments. An organisation is made up of a set of interdependent elements working together to achieve a company goal or objective. It is, therefore, important to relate all actions within an organisation to its impact on the global objectives. It is also important to realise that not all elements affect the system in the same way; some elements have less capacity than others. The elements with less capacity are the constraints of the system and limit the system’s ability to achieve its global objectives. If a (for profit) organisation had no constraints, then its profit would be infinite. In reality, there are very few constraints to any system.
The 5 Focusing Steps
Theory of Constraints uses this view to derive a 5 step process, called a ‘Process Of On-Going Improvement’ (POOGI), to improve any system. These steps are called the 5 Focusing Steps:
(Step 0 – Define the system’s goal or objective)
Step 1. Identify the System’s Constraint(s).
Step 2. Decide how to Exploit the System’s Constraint(s).
Step 3. Subordinate everything else to the above decisions.
Step 4. Elevate the System’s Constraint(s).
Step 5. If in the Previous Steps a Constraint has been Broken, go back to Step 1. (Warning: Do Not Allow Inertia to Cause a System Constraint)
The difficulty in
Drum – Buffer – Rope (DBR) is an operations scheduling methodology based on Dr Eli Goldratt’s Theory of Constraints (TOC) and first written about in The Goal and further explained in The Race. Drum Buffer Rope is just one part of the TOC Operations solution; it is the machine that sets the plan for Operations. However the second part of the TOC Operations solution is Buffer Management. Buffer Management is the monitor and control mechanism that ensures the machine is running well in execution.
Theory of Constraints takes a systemic view of a company or organisation. This means it treats the organisation as one and not as a number of different departments. An organisation is made up of a set of interdependent elements working together to achieve a company goal or objective. It is, therefore, important to relate all actions within an organisation to its impact on the global objectives. It is also important to realise that not all elements affect the system in the same way; some elements have less capacity than others. The elements with less capacity are the constraints of the system and limit the system’s ability to achieve its global objectives. If a (for profit) organisation had no constraints, then its profit would be infinite. In reality, there are very few constraints to any system.
The 5 Focusing Steps
Theory of Constraints uses this view to derive a 5 step process, called a ‘Process Of On-Going Improvement’ (POOGI), to improve any system. These steps are called the 5 Focusing Steps:
(Step 0 – Define the system’s goal or objective)
Step 1. Identify the System’s Constraint(s).
Step 2. Decide how to Exploit the System’s Constraint(s).
Step 3. Subordinate everything else to the above decisions.
Step 4. Elevate the System’s Constraint(s).
Step 5. If in the Previous Steps a Constraint has been Broken, go back to Step 1. (Warning: Do Not Allow Inertia to Cause a System Constraint)
The difficulty in