Information Technology Reference
In-Depth Information
A property
p
type
denotes the cell type:
P
=
{
p
type
:
L
→{
storage,transportation
}}
(A.2)
Boundary cells may be connected to a platform. Platforms represent
areas for incoming respectively outgoing articles. It is assumed that
articles can be taken from a platform for incoming articles as long as
articles are available and that a worker respectively forklift has to be
on an adjacent cell while picking-up an article. The same reasoning
applies to outgoing articles, i. e., as long as a worker or forklift is on
an adjacent cell and a platform for outgoing articles provides enough
free space, articles may be put onto it. For simplicity, it is assumed
that incoming as well as outgoing platforms are not limited in the
number of articles that may be put onto the platform (i.e., no upper
limit).
No update functions are defined:
U
=
∅
.
Macro-level: Constraints
Constraints define conditions under which a single action of an agent
may be executed successfully or fails. Actions may fail due to en-
vironmental circumstances which are not under the control of an
agent. Constraints are used to define in which case actions of two (or
more) agents are in conflict with each other. By default, all actions
of the agents are executed successfully and no two actions of any
agents influence each other. For this model, the set of constraints
C
=
{c
1
,c
2
}
is quite simple:
c
1
∈
C
: Only one worker or forklift may be at a specific cell at the
same time.
If two workers or forklifts try to move to the same cell at the same
time, a collision occurs. Due to this collision, both parties are
out
of order
for 5 minutes. The collision is represented by a specific
event type, namely
Collision
-events. Each time a violation of this
constraint is detected (i. e., more than two agents being on the
same cell or two or more agents moving onto the same cell), a
