How to model a normal distribution

[lindep]

Hi there!

For my bachelor thesis I need to model an arrival scheme of three vessels who are out at sea fishing for lobster. This can take about 30 days before they get into port again.

The arrival scheme is defined by different variables. Some of them are fixed, others I modelled with a distribution function based on previous occurences (then with a =VLOOKUP with RAND() in a table with a probability ditstribution for about 6 different values). Now I also would like to model some variables with an average and a standard deviation. So for example, the duration of bad weather (which defines the time needed to stay in port) is on average 4 days with a standarddeviation of 1. So the lower bound will be 3 and the upper bound will be 5.

Eventually I also need to run the model and i now have no idea how to. I heard that I should run the model by using loops? The arrival schema consists of four events that occurs in a cycle. Namely, 'At sea', 'To port', 'In port', 'Out port'. The first two times a vessel gets into port they get into port into a different port then where there headquarter and supplies are located. Therefore, when they get into port elsewhere, the bait supplies need to be transported. This will form another part of my research, comparing different transportmodes on which transportmode is best coordinated with the simulated arrival schema. Back to what I wanted to say, after two times getting back into another port the vessel gets back into port at their headquarter. After which the cycle of two times another port, 1 time own port starts over again. This is done for the three different vessels which they operate. These three vessels have a total allowable seadays per season, so when this number is reached the vessels need to get back into port at their headquarter and season is over. This is where the cycle should stop. Then I need to simulate the model X times (don't know how much to get reliability of 95%) and with the arrival schema conducted after the simulation I need to calculate the total costs for the different transport modes.

OK all the help is welcome! Thank you thank you!!

[zbor]

Upload example workbook with your inputs and desired output.

[lindep]

Thank you for answering. I made two posts since while typing the post I thought of another thing (the LOOP) that I needed to figure out and since that falls under another topic I posted it there as well.. Sorry for that!

I am now finetuning the variables and I'll upload it in 10minutes, thanks again.

[lindep]

Dear Zbor,

Attached you find my workbook for modelling an arrival schema. I currently typed out each period and calculated per period to get one season. But now I need to model it in a loop, where for example period 1 - 3 gets repeated until they've reached the maximum alllowed seadays per season. this should be summed over all three the vessels and is a total of 828 seadays max. The reason I need to loop 1 - 3 is that I need to take into account that sometimes (after approximately 2 times in another port like PE or EL) the vessels need to get back to CT which gives different values for example how many days it takes to get into port and how many days are spent in port.

I highlighted some things in the worksheet to hopefully make things more clear. Also for the variable which needs a normal distribution. Would love to hear your opion on the way i modelled it now and how i could model things better!


Thank you