How To Configure Your Production Workflow To Achieve Lean Production

Article2020Mar

How To Configure Your Production Workflow To Achieve Lean Production

 

Takt Time and Pitch Time

One of the most fundamental principles of Lean is for material to be pulled and flow down the value stream at the Takt Time throughput rate. Takt Time is the amount of time for each piece to flow down the production line in order to be able to meet the delivery order requirement. Takt Time is calculated based on the delivery quantity to be made, say 10000 units in a typical month of 21 working days of 8 hours per day (excluding lunch and tea breaks).

So, in this case, Takt Time is about 60 seconds:

Takt Time = 21 days x 8 x 3600 seconds / 10000 units  =  60.48 seconds

 

This Takt Time is the basis for configuring all production flow processes to about 20% less to provide a Pitch Time of 48 seconds. This 20% is the contingency factor for downtime, yield losses, rework and occasional material shortage.

Therefore, in this case, Pitch Time = 48 seconds

Pitch Time is the engineered process time to complete one unit at the standard work performance.

 

Lean 1st Principle

From the above, it can be said that the Lean 1st Principle is to establish the Takt Time.

 

Lean 2nd Principle

The 2nd Principle of Lean is to configure all process cycle times on the production line to about 20% less than Takt Time. This is the Nett Pitch Time

 

Configuring The Workstation Layout

In the concept of Lean, one-piece-flow is emphasized. Therefore, production lines with many processes should have one workstation each to work on the one piece flow.

If for some reason, the Pitch Time of a Capacity Constraining Resource (CCR) is more than Takt Time, the following formula can be applied to calculate the number of CCR workstations required to balance production:

No. of CCR Work Stations Required To Balance Production = Gross Pitch Time / Takt Time

 

How Should Work Stations Be Redesigned To Distribute Workload

The traditional Line Balance approach is to vary the number of work stations for each process so that process time is the same for every process . Although time is balanced, space, however, is not balanced. In Lean, processes with longer process times are redesigned and broken down into sub-processes of equal process time to achieve balance in time and space (see diagram at the top).

 

Conclusion

In order to achieve Lean Production Line design, the 3rd Principle of Lean is stated as follows:

 

Lean 3rd Principle

The 3rd Principle of Lean states that only one piece flows through each separate process in Gross Pitch Time, matching that of the Takt Time.

Applying the 3 Principles as explained above would provide the understanding on how to configure production workflow to achieve Lean production.