Instructions for running slam are located here.
The SLAM code for this problem is shown below and may also be copied from ~engelb/565/ele2.dat.
GEN, ENGEL, ELEVATOR, 12/2/94,10,Y,Y,Y/Y,N,Y/1,72; LIMITS,6,12,100; NETWORK; CREATE, EXPON(288); ACT/5,,TNOW .LE. 36000; WEIGHT QUEUE(1); ACTIVITY(1)/1,RLOGN(120.,60.); UNLOAD QUEUE(2),,6,BLOCK; ACTIVITY(1)/2,EXPON(240); GOON,1; ACT/6,,TNOW .GE. 36000 .AND. NNACT(1) .EQ. 0 .AND. NNACT (2) .EQ. 0,QUIT; ACT/7; TERMINATE; QUIT TERMINATE,1; ENDNETWORK INITIALIZE,0,40000; FIN;
The original problem description is available in week 15.
When there are more than 5 mowers waiting to be repaired, the customers take their mower to another shop. Don't use 5 8.5-hour days to represent the work week. Instead, use a 42.5 hour period to represent a work week.
The SLAM code for the above problem is shown below and can also be copied from ~engelb/565/mower.dat. Note that a SLAM time unit represents an hour.
GEN, ENGEL, MOWER REPAIR, 12/2/94,5,Y,Y,Y/Y,N,Y/1,72; LIMITS,6,12,100; NETWORK; CREATE,EXPON(0.4444); WAIT QUEUE(1),0,5,BALK(LOST),SORT; SORT SELECT,,CYC,,WAIT; ; Bob's service time, Bob is first because he is quickest ACTIVITY(1)/1,RNORM(1.,0.25),,DONE; ; Sam's service time ACTIVITY(1)/2,RNORM(1.214,0.33),,DONE; DONE TERMINATE; LOST QUEUE(2); ENDNETWORK INITIALIZE,0,42.5; FIN;
A combine with a 15 foot header and a 200 bushel grain tank harvests soybeans at 3.0 miles per hour in a field that is 1 mile long and 0.5 mile wide. The time to turn around at each end of the field is normally distributed with a mean of 25 seconds and a standard deviation of 10 seconds. Unloading occurs on the go at a rate of 6000 bushels per hour. Unloading may begin whenever the grain in the tank exceeds 100 bushels, and is assumed to occur continuously until the truck is filled. Unloading ceases whenever the combine grain tank is empty, but the truck continues to follow the combine through the field. If a truck is not available when the combine grain tank is filled, the combine ceases harvest, but will begin to unload immediately upon the arrival of a truck. Harvesting continues when the grain tank level drops below 190 bushels. Harvesting stops when the combine reaches the far side of the field, but the simulation continues until all the trucks have unloaded for that day.
The yield varies with position in the field. Function DTABL performs a two dimensional, linear interpolation of the table values for yield.
There are up to two trucks available for hauling the grain from the combine to the grain bin at the central farm headquarters. Initially, the trucks are in the shed at the farm headquarters and return there each night. The travel times are normally distributed with mean values given on the figure. The standard deviations are 5 mph for road travel, and 1/10th of the mean value for field travel. When a truck arrives at the field gate, it waits in line for its turn to be loaded. The travel time to and from the combine depends on where the combine is in the field. Unloading ceases when the combine is turning around at the ends of the field. It also ceases when the combine grain tank becomes empty. Naturally, when a truck is filled to capacity, it is released to return to the farmstead where it dumps its load. Harvesting starts at time 0, continues for 8 hours, then stops for 16 hours. Thus in each 24 hour period, only 8 hours are used for harvesting. A truck which completes its dumping after dark (during the 16 hour break), stays at the shed overnight.
Use the SLAM model in ~engelb/565/ called combine to simulate the attached network diagram for the above problem. The network portion of the code is in ~engelb/565/combine.dat. To do this, first copy combine.dat into one of your directories. Then copy it to fort.5 as you have done previously with SLAM code. Next run the SLAM code using the modified SLAM code that includes the Fortran code that has been written for this simulation by typing ~engelb/565/combine from the directory in which you have copied combine.dat to fort.5 (note you use ~engelb/565/combine rather than running slam as you did in previous problems).
The level of grain in the combine grain tank and in the bin at the farmstead will be plotted. Statistics on truck round trip time, truck utilization, combine utilization, and pit utilization will be collected by the model. Use the model to answer the following questions.
Combine speed (mph) Width of header (ft) Increased cost/year 3.0 15 No increased cost 3.6 16 $ 2,200 3.5 20 $ 5,750 3.1 25 $ 7,100The combine speed and header width can be changed in the combine.dat file by editing the INTLC line changing the SPEED and SWATH variables to appropriate values from the above table.
The SLAM network statement file is located in ~engelb/565/combine.dat. You should copy the file to your directory for use. SLAM has been recompiled with the fortran code linked for this problem. The executable file is ~engelb/565/combine. Since this is a large file, I would recommend using it in its present location. If you are interested in looking at the fortran code for this problem, it is located in ~engelb/565/combine.f.