1 Consider a service system with a single processing station

1. Consider a service system with a single processing station, a waiting area, and variability in service times and arrival times of customers. If the service system operates at 50% utilization, there will be no waiting time in the waiting area.

True or False

2. Quality at the source refers to the effort to catch and correct any mistakes as they are being made by those that are making them.

True or False

Solution

Let us illustrate this problem as per queuing theory problem M/M/1 type as per Kendall’s notation

In such case Let,

Arrival rate = a per hour

Service rate = s per hour

Thus utilization Rate = a/s x 100 = 50 percent ( as given )

Therefore, S = 2.a

Average waiting time in the queue in the waiting area = a/ s x ( s – a )

= a/ 2a.(2a-a) = a/2.a^2 = 1/ 2.a

Since waiting time in the waiting area is ½.a and “a” is an integer , therefore waiting time in the waiting area CANNOT BE ZERO

It is therefore “FALSE” to state that there will be no waiting time in the waiting area

ANSWER : FALSE

Quality at the source is a lean manufacturing principle which defines that quality output is not only measured at the end of the production line but at every step of the productive process and being the responsibility of each individual who contributes to the production or on time delivery of a product or service. In a practical sense it would involve each operator checking his or her own work before the part/component or product is sent to the next step in the process.

Therefore it is “TRUE” that Quality at source refers to the effort to catch and correct any mistakes as they are being made by those that are making them

ANSWER : TRUE