servicetime

Service time, sometimes written as service time, is the duration spent performing a service for a customer or task. It is the time from the start of service to its completion, excluding any waiting period. As a fundamental variable in queueing theory and operations research, it characterizes how long a service process takes on average and how much it varies.

In business operations and manufacturing, service time informs staffing, capacity planning, and throughput. In information technology and computing, it describes the time a request spends being processed by a service or microservice, contributing to latency and overall performance metrics.

Measurement and variability are central to the concept. Service time is usually recorded per service event or per unit of work and can follow various statistical distributions (for example, exponential or gamma in theoretical models). The average service time, along with arrival rate, helps determine system performance through metrics such as utilization and expected wait times. Variability in service time increases the likelihood and length of queues, affecting customer experience and resource requirements.

Related concepts include response time, which combines waiting time and service time; cycle time; service level; and throughput. A simple example is a cafe: the time from when a barista begins preparing a drink to when it is handed to the customer constitutes the service time.