Server task errors involve incorrect
server performance such as improper arrangement of surgical instruments by operating room staff; indented
holding trays exemplify a Poka yoke preventing such error. Server treatment errors relate to their behaviors
during customer contact; Eye contact establishes a relationship between the customer and the sales person
(Henricks, 1996). If customers equate eye contact during a personal service encounter with high quality,
transaction forms requiring the server to indicate the eye color of the customer constitutes effective fail safing.
Tangible (i.e., physical and environmental) server errors can also be fail safed; bus station benches are designed
as sequential chairs with fixed armrests to prevent transients from sleeping on them, and hotels use paper strips
around clean linens to ensure the detection of use by housekeeping. Customer-based errors occur before, during,
and after the service encounter. Customer preparation errors include inadequate service access or customer
expectation management. Dental patients often forget appointments between intervals; the error is generally
fail-safed via a telephone call or post card shortly before the scheduled service. The spectrum of customer errors
during the encounter include incorrect flow or queue, needs specification, or coproduction. Cable TV subscribers
often request service calls when they have unknowingly changed the required channel setting; the needs
determination process is poka-yoked by always requiring the customer to change from, then back to, the required
setting.