In this paper we present a specialized system for
temporal reasoning representing possibly uncertain qualitative
and quantitative constraints relative to temporal intervals
in a homogeneous framework. The underlying logic is that
of Allen, which we have extended to include quantitative
temporal information. Intervals are still assumed as primitive
entities while, to represent metric information, time points
are introduced only at the algorithmic level. We illustrate
the properties of the temporal representation, the algorithms
used for constraint propagation, and their complexity.
We show how the system can be used to schedule manufacturing
operations in a small factory.