The family of shop problems has the constraint fields shop type, machines of the operations, number of machines, number of jobs, processing times, no-wait, no-idle, transportation delays, a server, batch setups, release dates, deadlines and precedence constraints between jobs, and the completion-time objectives.

A problem $\alpha \mid \beta \mid \gamma$ with $\alpha$ one of $O$, $F$, $J$, possibly followed by a number of machines, is one specification of this family. Without an entry on machine sets, the operations of an open shop or flow shop occupy the machines by position and those of a job shop occupy dedicated machines. For example $F2 \mid\mid C_{\max}$ and $J \mid r_j \mid L_{\max}$ are the specifications below. The concept on one family for shops joins these problems and the preemptive shop problems into a single family with an interruption field.

Theorem. A specification that is field by field a special case of another describes a special case of the other's problem, and a specification that reduces to another describes a problem whose decision version reduces to that of the other. In particular $F2 \mid\mid C_{\max}$ is a special case of $J \mid r_j \mid L_{\max}$.