Can We Reduce those Long Queues in front of Grocery Stores by 50% ?

(This is the English translation of my original Sinhalese article published on 24th March 2020)

Sri Lanka, as the rest of the world, has taken all the steps to prevent the COVID19 breakout by all means. The government has declared police curfew across the country to reduce the mobility of public which believe to be the best preventive measure to bar the spread of the disease. Even though such measures have proven to be very successful in flattening the COVID19 infection curve, the general public has to undergo tremendous difficulties in terms of satisfying their day today needs.

There were occasional lifts in the curfew for limited period of time where general public used that time to do the shopping of essential items. That was the point where the problem started. As all the people were gathering at the supermarkets at the same time and the requirement of maintaining at least on meter length distance between counterparts have created lengthy queues, some of which have extended for few kilometers.

Current Status

When I reached to the supermarket, it was around 10.40 in the morning and I joined a queue where about 80 people standing in front of me. It took around 1 hour for me to reach to the main entrance and only 50 people were allowed inside at any given time. I was able to collect the items in 20 minutes but I had to wait another 30 minutes in the cashier queue to settle the bill. There were 4 cashier counters working at that time. The situation is drafted below using a basic level Value Stream Map.

There are three main segments as indicated in above draft.

1. Queue and Entrance
2. Inside the outlet
3. Cashier counters and exit

It was observed that it took around 3 minutes per person average time at each counter. Below is a further analysis of the observed times at each segment.

The Yamazumi with the current state timing suggests that the per person cycle time in the cashier area determines the per person cycle time of the queue in the entrance. Other notable fact is every 24 seconds a person finishes collecting items and ready to go the cashier. Therefore it suggests that the Bottleneck process of this super market lies in the Cashier & Exit area. More importantly if the cashier can be improved then it will directly impact to the rate of entrance and hence the queue length.

Target State

With the current state Yamazumi analysis, it is evident that the cashier time per person could be reduced up to 24 seconds per person without impacting the buying time of a customer. If the Cashier time can be reduced up to 24 seconds, then the rate of entering in to the super market will improve by 50% hence reduce the 800 m length queue to 400m queue.

How to reduce the cashier time by 50% ?

With the Yamazumi, it is clear that by improving the cashier capacity, the time per person could be improved. In general, the suggestions would be to increase the number of cahsier counters or increase the number of people to support the cahsier etc. That is where the "Lean thinking" contrast the general thinking.

When applying lean thinking, first I have grasped the situation (GTS) through simple tools like Value Stream Mapping (primary stage), Yamazumi and identified bottleneck to improve. Also above tools help to understand the connectivity of the dependent and independent variables. In this case the dependent variable is the lenght of the queue and the vital dependent variable is the time per person spent at cashier.

To improve the bottleneck process, further motion analysis has to be conducted on the cashier's work. To identify the real facts we must do "Gench Genbutsu" or go to the real place, people and process. It is highly unlikely that someone would come up with practical suggestions by analyzing excel databases or arguing in boardrooms. One must come to the value adding point to see things from his/her own eyes to generate grass root level solutions. Below is an actual video footage of the cashier processing the orders.

If you have not calibrated your eyes to see eight deadly wastes discussed in basic lean principals, this lady may appeared to be doing a great job. Yes, she is doing a great job with an immense effort to keep the queue moving as fast as possible. But did you notice the "wastes" that she is doing while she is doing her routine work?

To understand a the concept of "waste" one must understand the concept of "value". To get a better understand about waste and value please go through this article (shorturl.at/flopq). Any activity that does not add value to the process can be determined as a waste. In this scenario, bar coding the items (This is not adding value in terms of the bigger picture, but let's consider this as value adding for this incident), issuing the receipt and change money/ card are the value adding activities in relation to the customer.

Look at the video with the "waste" mind set. you will see that the lady is stopping her job and waiting for various reasons, spend two three times to read the bar code, multiple unwanted movements to get the items and many more. In order to thoroughly analyse the motion of the cashier, below motion analysis table can be utilized. The work done by the cashier within 3 minutes has been analysed below.

After doing the analysis, what is witnessed at gemba could be quantified. With the analysis, it is clear that only 11% of her work is contributing for value adding activities. rest of the 89% can be considered as wasteful acts. Our target was to reduce 50% of the cashier time and, after the motion analysis more than 80% of improvement opportunity could be uncovered.

This is a result of just one observation of one counter. To have an unbiased and more accurate result, it is recommended to take minimum 10 such observations covering all the counters.

What is the step after the "Motion Analysis" ?

With the motion analysis, the bottleneck process has been further drilled down and potential causes for "high time consumption" was decoded. The next step is to introduce countermeasures for the identified potential causes. For that, the most effective methodology is the Gemba Kaizen approach. Through gemba kaizen, the team can implement improvements within very short period of time, with lowest investment and cashier's consent. One of the main objectives of gemba kaizen is to apply ECRS (Eliminate, Combine, Rearrange, Simplify) approach for identified wastes. Following are some of the gemba kazen suggestion to ECRS the process.

• Place the bar code machine such a way that reduces the distance between the items and the machine to reduce unwanted hand movements of the cashier
• Fix the bar code machine in order for the cashier to punch the item with confidence
• Design a rack for the customer to place the trolley at waste height in order for him to pick up the items without bending over and over again
• Educate the customers to place the items with bar code pointing upwards which helps the cashier to identify the place of the bar code at a glance
• Make sure all the items are labeled with bar codes
• Place the cashier parallel to the customer to reduce unwanted motion.
• Make sure the balance coins and cash available any time through simple "Min Max" visualization.

Above are some of the suggestions which came to my mind as a customer. A brainstorm session between the management and the cashiers could generate more practical ideas than those which are mentioned above. The important thing is to implement the suggestions as soon as possible. Most of the suggestions mentioned could be implemented overnight without spending a single rupee.

It should be kept in mind that each kaizen is an unproven experiment to prove the hypothesis that each kaizen could reduce the per person cashier waiting time. Therefore after implementation, the results has to be monitored and verified. If the desired results are not achieved, more kaizen has to be experimented, having the motion analysis results as the basis.

The most important thing is that such an improvement will not valid only for this kind of "special day". Those wastes were there in the process on other "normal" days as well. Apparently, due to COVID19, people were forced to adhere to set of standards (staying in a queue, only 50 people allowed inside, etc) and those standards helped to highlight the wastes in the system.

What management can do is to reduce the waste in the system, with negligible investment of money and time. It will drastically improve the process so that the store could run only with 3 or 2 cashiers in "normal days". If the waiting time is reduced in the cashier, it will give better customer satisfaction which will create a differentiated competitive advantage in the market place where there is a fierce competition emulating from existing and new players. And the other point is that any kaizen implemented in one branch, and if it is proven to be successful, those kaizens have to be replicated in all the branches as soon as possible. And continuously challenge those improved processes again and again and do further kaizen. There is no limit for kaizen!