“Critical Process” – Reality Check

by Guest Posting on 2012-05-30 05:39:29

“Critical Process” as we commonly know is a process or path that takes the longest time for execution or completion. In case of assembly lines this is commonly assessed in terms of the backlog of work for a particular assembly station, during continuous flow of work.

Is the “Critical Station” really critical? Or is it because we are following age old assembly line structures designed by experts long ago without questioning whether something can be done differently?

We take a look at one such assembly line “names omitted”, to understand that a “Critical Station” may not be critical at all.

This assembly line comprised of 21 assembly stations end to end excluding the sub-assemblies involved. One station near the end but before the testing bed consumed the largest time frame when compared to the others and was the “Critical Station” that determined the line capacity. Also two stations before this Critical Station was the station with the fastest throughput time.

So these four stations were considered for a study of all the activities involved and checked for activity portability among them. This resulted in the identification of a particular item that can be fitted two stations before the critical station.

Once implemented, the “Critical Station” lost its position and the assembly line became balanced as to the distribution of time-consumed for its various stations. This resulted in an increase of line speed by 13.33%. This coupled with the introduction of double bin, tailor made racking and location change of parts for reducing movement distance, resulted in an overall line speed increase of 50%.

The motto is – Do a reality check with an open mind before promoting a process as the Critical One.

Author
Shouvik Chattopadhyay
Six Sigma Green Belt
PGD Transportation & Logistics Management

Specialties
SCM, Lean 6 Sigma, Supply Chain Process Optimization and Process Quality Analysis, Solution Design, 3 / 4 PL Project Operations Management, Vendor Development, BTS Warehousing and Distribution Network Design and Setup, Double Bin, Kanban, Kaizen, RTF, DPR, Inbound Logistics, Outbound Logistics, National Logistics, Regional Warehousing and Distribution, JIT, Supply Chain Risk Management, FMEA, Safety Incident investigation and Root Cause Analysis, HAZMAT and Training & Consultancy