Time scales
A time scale, in this context, can be defined as the period bet-
ween the point in time when a situation is perceived up until in-
formation is gained about the results of the measures that are
taken (Swedish Rescue Services Agency, 1998b). A time scale
is not just a measure of how far planning in advance stretches. It
is also a measure of reaction speed from impression or informa-
tion, via assessment to decision (Swedish Rescue Services Agen-
cy, 1998a). The time scale, quite simply, describes the period for
which certain information, decisions or authority is applicable
and within what period followup from executed measures and
such is received. Each decision domain must be able to handle se-
veral different time scales, but a superior decision domain limits
the lengths of the time scales a subordinate domain can handle.
Each decision domain must be able to handle both long and
short time scales. The short time scale concerns being able
to handle the prevailing situation. The long time scale con-
cerns planning for the future, visualising the consequences of
the present situation. This, depending on the decision domain,
can concern potential events taking place in five minutes, five
days or perhaps even further into the future. That this is a
sliding scale between short and long time perspectives can, for
example, mean the requirement of continual awareness of po-
tential developments from the present time up until a certain
time in the future or the occurrence of a specific event. The
ability to handle different time scales is also an important aspect
of a tactical approach.
Short or long time scales are not evaluated in any way. We can-
not say that it is better with long time scales than short, or vice
versa (Swedish Rescue Services Agency, 1998a). Each decision do-
main has its time scales, and it is the needs and demands of the
situation that determine their suitability and validity. A long time
scale in one situation can be short in another. Four hours can, for
example, be a long time in the case of a traffic accident or a short
time in the case of a major forest fire.
Time scales are not only forward reaching. A decision domain
must also take past events into account, and, obviously, ongoing
events. In the same way as for the future, this can, depending
on the decision domain, concern occurrences that took place five
minutes, five days or even longer ago. And also in the same way
as for the future, the past must be accounted for on a sliding scale