Contact Center | Staffing and Trunking Relationship

Many call center make the mistake of applying an arbitrary ratio of trunks to staff in their resource design. Some assume a one-to-one ratio and have an equivalent number of trunks to match the bodies in chairs. While this may be appropriate for some centers, it will be a mismatch for others.

Consider the two call center scenarios:

Call Center A:

Ring | 6 Sec, Delay | 30 Sec, Talk | 240 Sec, After-Call Work | 60 Sec

Call Center B:

Ring | 6 Sec, Delay | 60 Sec, Talk | 240 Sec, After-Call Work | 30 Sec

The right match of staffing to trunking is essential for proper resource planning. The number of trunks in place controls the flow of calls that will be routed to the staff and therefore has a major impact on attainment of service goals. And like wise, the number of staff in place will affect delay times in queue and trunking requirements.

Care should be taken to ensure that there are enough trunks in place to provide a good level of service to callers. It is natural to assume that a call center might over-trunk to make sure enough inbound facilities are available to callers, so that a minimal number reach a busy signal, especially since the cost of a trunk is so much less than the cost of an agent.

However, adding too many trunks without corresponding additions in staff is like increasing the size of a doctor's waiting room without adding more doctors. More people can enter the lobby (the call center queue), but everyone there will wait longer to be served. And since there are costs associated with this delay time if the call center is using toll-free services, the call center will be paying dollars additional for the longer wait time.

This type of situation happens often when the trunking is controlled by a separate IT or telecommunications department and staffing is controlled in the call center. The telecom specialist may note that callers are getting a busy signal during certain periods of the day and decide to increase the number of trunks.

Without a corresponding increase in staff, more caller will enter the queue and immediately fill up the new trunks and blockage may continue. If the reason for the busy trunks is because staffing levels are too low, then callers will still get busy signals and more people will be waiting in queue for longer periods of time, causing telephone costs to rise and delays to increase.

In making the decision about how many calls to accept versus limiting the number that come into queue, it is important to consider how important it is to capture the call or not. In a sales situation, the call center will most likely want to let every call in, since responding with a busy signal might lose a potential customer. On the other hand, where the caller represent more of a "captive audience", it may benefit the center to allow in only the number of calls that can be handled in a reasonable amount of time with the assumption that the blocked callers will call back to be handled later.

Services/Blockage Objectives

Once the telephone trunk workload has been determined, the number of needed facilities can be determined. Just as in staffing, the number of resources required is based on a service goal. In the case of the incoming telephone trunks, the goal is not a delay or speed of answer definition, but rather a "grade of service" one that define blockage. In other words, the number of trunks will be based on what percentage of calls it is acceptable to block and deliver a busy signal, forcing the caller to try the call again.