
## Algorithm 1 **Myopic Construction**

1: Set E
o = E
2: E
u ← ∅
3: **while** E
o 6= ∅ do 4: Select the most critical event E from E
o, that is the event with the smallest number of available timeslots 5: if E can be assigned to at least one timeslot **then**
6: Select some available timeslot T for E
7: Assign E to the timeslot T 8: **else**
9: E
u ← Eu ∪ E
10: **end if**
11: E
o ← Eo\E
12: **end while**
As mentioned above, timeslots of rooms of class Ri1 **are preferable to the ones of class**
Ri2 and Ri3. The randomized assignment procedure generally considers **this aspect,**
however allowing a certain deviation from the rule. This is done as we have been able to observe that the assignment of events to timeslots following only a single order does not lead to satisfactory results. In this case, the choice of timeslots simply is too restrictive.

It has been pointed out in this context that the probability of assigning events to timeslots of Ri1 → Ri2 → Ri3 **could be expected to be greater than the one of** the order Ri2 → Ri1 → Ri3**. While we generally agree with this comment, other**
probabilities than 0.5 for both orders have not been investigated yet. Consequently, subsequent experiments certainly will have to examine the influence of this control parameter on the obtained results.

## Experimental Results

The constructive approach has been tested on the first seven benchmark instances of ITC 2007 track 3. These are the instances that initially have **been made available by**
the organizers of the competition. In February 2007, only a few weeks before the submission deadline, seven more instances followed (comp08.ctt–comp14.ctt**). Obviously,**
experimental investigations had to start considerable earlier, and we therefore had to conclude on the effectiveness of the approach based on these early seven instances.

After 1000 repetitions on each benchmark instance, we computed the number of trials in which all events have successfully been assigned to timeslots, given in Table 1.

Table 1 Number of trials in which all events have successfully been assigned (out of 1,000 trials)
4

| u = ∅      |              |
|------------|--------------|
| Instance   | Cases with E |
| comp01.ctt | 1,000        |
| comp02.ctt | 354          |
| comp03.ctt | 377          |
| comp04.ctt | 1,000        |
| comp05.ctt | 0            |
| comp06.ctt | 953          |
| comp07.ctt | 827          |
