Page 382 - Design for Six Sigma for Service (Six SIGMA Operational Methods)

342 Chapter Ten

with the customer. The service may be making reservations, catalog
ordering, or providing a customer support service. In a telephone service
system, issues to address include the following:
• Overflow calls. The caller receives a busy signal.
• Reneges. The customer gets in but hangs up after a certain amount of
time if no assistance is received.
• Redials. A customer who hangs up or fails to get through calls again.

The most important criteria for measuring effectiveness is service time. The
customer is simply interested in getting the service or ordering the product
as quickly as possible. The customer’s ability to communicate the need is
critical to the service time.

Calls usually arrive in the incoming call queue and are serviced based on the
first in, first out (FIFO), or first in, first serve, rule. Some advanced telephone
systems allow routing of calls into multiple queues for quicker service.
Processing of a call is done by a single resource. Duration of the service
depends on the nature of the service. If the service is an ordering process, then
the service time is short. If the service is a technical support process, then the
service time may be long or the call may require a callback after some
research.

Examples of Telephone Services
Technical support services (hotlines) for software or hardware, mail-order
services, and airline and hotel reservations

Telephone Service Performance Metrics

Service Time
Usually the average service time per call can be used as a measure of
efficiency for telephone services.

Waiting Time
Average waiting time per customer is an important measure for telephone
service efficiency and is closely related to customer satisfaction.

Abandonment Rate
Abandonment rate is the proportion of customers who give up waiting and
abandon the service. It is usually highly correlated with waiting time and is
an important measure of customer satisfaction.