Table 1 shows how different combinations (first column)
result in different types of barrier, which require different
types of management. For passive hardware the emphasis is
on design and installation. For active hardware the involvement
of workers becomes important in the functioning of
barriers and aspects like inspection and maintenance, competence
(at either skill, rule or knowledge based level) and
commitment are highly relevant.
2.3. Recursivity
One other important aspect of the approach towards barriers
and their management outlined above is the notion of
recursivity. That is, some delivery systems function as Russian
dolls or using a common Dutch expression, according
to the ‘Droste effect’.2 For instance, the delivery of competence
as an element of proper barrier functioning also
implies the delivery of competence to those who deliver
such competence. Similarly, inspection and maintenance,
being also a delivery system, again requires competence,
procedures and commitment to be of sufficient quality
and so on. This essential characteristic should be kept in
mind when envisioning the management model or using
the ARAMIS audit. Fig. 2 provides another overview of
the delivery systems to illustrate this characteristic. For
the sake of clarity not all arrows have been drawn in the