Here are the hand simulated examples for you to look at. These timelines simply take a set of typical input values to the system, and then interpret the rules of the tug behaviour based on those inputs. Using the same set of inputs the simulation has been done twice using the baseline tug behaviour and the protocol 1 tug behaviour. This should be enough to illustrate the main points of the tug's behaviour. The most interesting spots occur where there are differences between the behaviour of the tug under the two protocols. Particularly, at time T=33.44 when Tanker A indicates that it has finished loading, and the tug has just left, unloaded, for the harbour to retrieve Tanker B. Under protocol 1 the tug will turn around and pick up A, but in the baseline case it continues to travel to the harbour to pick up B. Your task is to discover through your simulations how much these differences in policy affect queue lengths, tug utilization etc. Also, note at time T=87.12, the tug will be forced to turn around and return to the harbour, due to an incoming storm. It's important to consider such details of the implementation. Please note that this timeline is for illustrative purposes only. Your simulations should not generate timelines like this as output. (Although it might be a useful debugging technique.) --Andy ------------------------------------------------------------------ Events (All times in hours): T=0 T=15.71 Tanker A arrives - type 1, Loading time = 16.48 T=33.78 Storm of length = 3.01 T=33.43 Tanker B arrives - type 3, Loading time = 33.33 T=50.67 Tanker C arrives - type 2, Loading time = 24.75 T=58.00 Tanker D arrives - type 3, Loading time = 39.47 T=70.35 Tanker E arrives - type 3, Loading time = 36.49 T=86.97 Tanker F arrives - type 3, Loading time = 33.68 T=87.12 Storm of length = 3.74 The tug takes 0.25 hours to make a one-way trip unloaded, and one hour to make the same trup when towing a tanker *including* the time to pick up and drop off the the tanker. If a tug is forced to turn around in a storm (or because it's been called-for in the Policy 1 version) then we'll assume that the time back to the port is the same as the time of the journey when the storm hit. ie. if the tug leaves the harbour empty and travels for 0.1 hours when a storm hits then it turns around and arrives at the berths 0.1 hours later. 100 HOURS OF ACTIVITY OF BASELINE TUG: Empty Berths Time Actions 3 T=0 Tug resting at berths, all berths empty, no tankers in harbour 3 T=15.71 Tanker A arrives, tug leaves berths 3 T=15.96 Tug arrives at harbour, picks up Tanker A 2 T=16.96 Tug arrives at berths with Tanker A, tug idles 2 T=33.43 Tanker B arrives, tug leaves for the harbour 2 T=33.44 Tanker A finished loading, calls for tug 2 T=33.68 Tug arrives at harbour, picks up Tanker B 2 T=33.78 Storm begins, tug continues berthing action 1 T=34.68 Tug arrives at berths with Tanker B, tug idles due to storm 2 T=36.79 Storm ends, tug begins deberthing Tanker A 2 T=37.79 Tug arrives at harbour, drops of Tanker A, heads back to berths 2 T=38.04 Tug arrives at berths, idles 2 T=50.67 Tanker C arrives, calls for tug 2 T=50.92 Tug arrives at harbour, picks up Tanker C 1 T=51.92 Tug arrives at berths with Tanker C, tug idles 1 T=68.00 Tanker D arrives, tug starts out for the harbour 1 T=68.01 Tanker B finished loading, calls for tug 1 T=68.25 Tug arrives at harbour, picks up Tanker D 1 T=69.25 Tug arrives at berths, drops off Tanker D, picks up Tanker B 1 T=70.25 Tug arrives in harbour, drops of Tanker B, heads to berths 1 T=70.35 Tanker E arrives, tug continues to berths 1 T=70.50 Tug arrives at berths, turns around and goes to harbour 1 T=70.75 Tug arrives at harbour and picks up Tanker E 0 T=71.75 Tug arrives at berths and drops of Tanker E, tug idles 1 T=76.67 Tanker C finished loading, tug picks it up and heads to harbour 1 T=77.67 Tug arrives at harbour, drops off Tanker C, heads back to berths 1 T=77.92 Tug arrives at harbour, tug idles 1 T=86.97 Tanker F arrives, tug heads to harbour 1 T=87.12 Storm begins, and the tug turns around after 0.15 hours of travel 1 T=87.27 Tug arrives at berths 0.15 hours later and idles due to the storm 1 T=90.86 Storm ends, tug leaves for harbour 1 T=91.11 Tug arrives in harbour and picks up Tanker F 0 T=92.11 Tug arrives at berths with Tanker F, tug idles 0 T=100.00 End of simulation 100 HOURS OF ACTIVITY OF POLICY 1 TUG (SAME EVENT SEQUENCE): Empty Berths Time Actions 3 T=0 Tug resting at berths, all berths empty, no tankers in harbour 3 T=15.71 Tanker A arrives, tug leaves berths 3 T=15.96 Tug arrives at harbour, picks up Tanker A 2 T=16.96 Tug arrives at berths with Tanker A, tug idles 2 T=33.43 Tanker B arrives, tug leaves for the harbour 2 T=33.44 Tanker A finished loading, calls for tug, tug turns around * 3 T=33.45 Tug arrives at berths, begins deberthing Tanker A 3 T=33.78 Storm begins, tug continues deberthing action 3 T=34.45 Tug arrives at harbour, drops off A, picks up B, despite storm 2 T=35.45 Tug arrives at berths, drops off B, idles due to storm 2 T=36.79 Storm ends, tug idles 2 T=50.67 Tanker C arrives, tug goes to harbour 2 T=50.92 Tug arrives at harbour, picks up Tanker C 1 T=51.92 Tug arrives at berths with Tanker C, tug idles 1 T=68.00 Tanker D arrives, tug starts out for the harbour 1 T=68.25 Tug arrives at harbour, picks up Tanker D 0 T=69.25 Tug arrives at berths, drops off Tanker D, tug idles 1 T=69.78 Tanker B finished loading, tug picks it up 1 T=70.35 Tanker E arrives 1 T=70.78 Tug arrives in harbour, drops of Tanker B, picks up Tanker E 0 T=71.78 Tug arrives in berths with Tanker E, tug idles 1 T=75.67 Tanker C finished loading, tug picks it up and heads to harbour 1 T=76.67 Tug arrives at harbour with Tanker C, heads back to berths 1 T=76.92 Tug arrives at berths, tug idles 1 T=86.97 Tanker F arrives, tug heads to harbour 1 T=87.12 Storm begins, and the tug turns around after 0.15 hours of travel 1 T=87.27 Tug arrives at berths 0.15 hours later and idles due to the storm 1 T=90.86 Storm ends, tug leaves for harbour 1 T=91.11 Tug arrives in harbour and picks up Tanker F 0 T=92.11 Tug arrives at berths with Tanker F, tug idles 0 T=100.00 End of simulation * This is the really interesting case where Policy 1 will differ from the baseline