ﬁxed or tight timescale). It does, however, have the advantage of being particularly
simple to perform, if it is approached in the right way and with the right mindset.
In many ways its success is as much about having the right mindset as it is to do
with using the technique itself. All involved stakeholders need to buy into the
concept of timeboxing and into an agreement about the proposed timescale of the
This section provides guidance on how to use the technique in an eﬀective way.
Without eﬀective timeboxing, focus can be lost and things will run out control.
Much of what is discussed here is to do with planning, control and keeping a clear
focus on what actually has to be delivered at the end of the timebox. It is for this
reason that there is a very close relationship between timeboxing and the clear
prioritisation of deliverables. In addition to this, there is also an important reliance
on an ability to estimate the complexity and duration of the tasks to be undertaken.
It is also vital that whoever is actually undertaking the work within the timebox
should be involved in the development of these estimates.
Description of the technique
There are many deﬁnitions of a timebox. Here we will distinguish between two
An outer or overall timebox is the time between the start and end dates of a
project, or a major stage, or the date on which a major set of deliverables are due.
As a technique, timeboxing is most signiﬁcant when the end date is not movable.
Inner or lower-level timeboxes are nested, like Russian dolls (quite appropriate
when used in conjunction with the MoSCoW approach to prioritisation, Technique
55) or wheels within wheels within the overall timebox, to provide a series of ﬁxed
times by which interim products are to be delivered or partially produced. This
leads us to consider carefully the interrelationships between the various inner
timeboxes in terms of their dependencies and overlaps.