Value Stream Map
The value stream map below shows a process of customer interaction with a teller in a bank. The time indicated shows the average time taken per customer for the 100 customers who were surveyed. The arrow indicates the direction of flow from one step to another, and the approximate time taken to finish each step is also shown.
Ask for Verification Doc.
Inform the Customer
of the Issue
Resolve the Issue or
Ask for Assistance
Thank the Customer (End)
Conduct Verification Process
The key metric in this value stream is time taken at each step and the efficiency of each bank teller. The bank usually wants employee with a quick understanding of issues, who can handle a customer’s issue within a short period of time. It would be exhaustive and annoying to the customer if the teller inquires too much before serving. Therefore, the aim is just to simply ask what is relevant and sufficient to understand the issue at hand.
· Lead Time = 1 + 0.5 + 0.5 + 0.5 + 0.5 + 1 + 1 + 0.5 = 5.5 minutes.
The entire process takes 5.5 minutes to start and finish. There is a 2 percent lag period, therefore we can say the process is 98 percent efficient.
· Process Time = 5.5 minutes / 8 = 0.6875 minutes
One teller serves one customer, from the time of arrival at the teller till the end. However, the teller may be required to seek external assistance that serves to cause more delay. They would still try to ensure they are well equipped to address almost all issues at once.
Current State Summary Metrics
· Total Lead Time = 1 + 0.5 + 0.5 + 0.5 +0.5 + 1 + 1 + 0.5 + 0.5 = 6 minutes
· Total Process Time = 6 minute / 8 = 0.75 minutes
· Activity Ratio = 0.75 minutes / 6 = 0.125
· Rolled Percent Complete and Accurate = 100% – (0.125* 100%) = 87.5%
Current State of Value Stream
The value stream is quite efficient, though it needs multiple lines of operation based on the average demand at a given time. For a bank with an average 500 daily customers, they will need an average of six tellers to serve that many customers per day. However, that will depend on the efficiency of each operator. Any daily issue at any given time means serving fewer customers and raising the probability of not serving everyone at the branch. In return, that will affect the work in progress and, as a result, impact the bank’s efficiency.
However, there is a 0.5 minutes delay before a customer is served and released. This time would increase in the event that the teller needs to obtain information that is not readily available to him/her and the customer. At that instance, the delay time would undoubtedly increase which can undermine quality and efficiency. On the other hand, in the event they both have sufficient information, then the whole process is smooth and no bottlenecks would exist to negatively impact performance.
Tupa, J. (2014). Performance measurement for efficient lean management: theory and case study. International Journal of Lean Enterprise Research, 1(2), 116.
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