1. DCT Analysis

2. Concepts: UML-like class model of essential classes and actions.

3. Conceptual model: Simplest model: connected queues. More advanced models differ between 3 classes of trucks and various actions of crane.

4. Essence: 2 connected queues. (only 8 exceptions out of 500) Most important parameters:  k (keeper occupation rate)  c (crane occupation rate) Assume M/D/1 queues (exp arrival, const processing) if  k ≥  c, then crane queue empty. If  k <  c, then average queue length keeper: C/(1-  k ) average queue length crane+keeper: C/(1-  c ) (approximately for some constant C) If e.g.  k = 0.9 and  c = 0.91, then keeper queue 10C and crane queue C. Greatest capacity problem with crane, though! c.f. Arena model DCT.doe in "examples" directory.

5. Problem: large queues; keeper queue largest. Causes: keeper occupation rate too high, also crane capacity? Crane queue waiting time 35% of keeper waiting time, so crane capacity is an issue! Solutions: increase keeper productivity. Investigate crane occupation rate. Increase crane productivity also.

6. Short-term temporary solution: increase working hours. Cost: extra payment to workers, which is manageable ("business is booming"). Benefits: less dissatisfaction of customers. Longer term solution for keeper problem: use IT! Crane solutions (in any combination): - faster crane - double queue - improve container storage

7. Assignments 4-5 assignments throughout the course Bonus for exam: max. 2 points Bonuses awarded for overall quality and nice parts (e.g. concepts, problem analysis and suggestions). This assignment: score ≥ 8: full bonus (.4) OK(7): small bonus (.2)

8. Impression Much enthousiasm and hard work. Some reports were very good (talent or experience). Need course? Others need not despair. Hopefully course will help you.