Resource Priorities

Question

question

Luis T7 asked Feb 12, '19 Luis T7 commented Feb 18, '19

Resource Priorities

Hello,

In this model,

Right now using only priorities the operator is kinda doing the desire task sequence, but sometimes it will unload the box on Test_1 and before doing the setup on that station, if another test station just finished processing the operator will first transport that box and then do the set up, or sometimes the operator will be moving around carrying more than 1 box.

What should happen:

Boxes Arrives at IPK then Operator Picks a box and unload it on any test station and performs the setup for that box on the respective station, once the test is done operator will move the box by percentage:

90% -> Next Process (Sink)

10% -> WIP Debug

If a box arrives to debug station, operator will start working on the debug process, BUT if a test station finishes, operator will stop the debug process and do the main activities, which is connecting the units to the test stations and removing the units from the test stations.

Operators should not carry more than 1 box at a time.

Thank you in advance for the support,

Regards,

Software Version:

FlexSim 19.0.0

operators

sn-resource-priorities.fsm (24.4 KiB)

· 4

Joshua S commented · Feb 13, 2019 at 10:20 PM

Looking at the flow of items into your system, the operator will never be able to debug a part, does the operator need to be there the entire time the part is being debugged?

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Luis T7 commented · Feb 13, 2019 at 10:33 PM

@Joshua S

Hello,

That is kinda what the model is trying to prove, with 1 operator it will take about 1:30-4:00 hours to finish debuging only one part and the WIP for the bug will be increasing a lot which leads to a several increment in INVENTORY $$ on shop floor if:

The operator has to receive and connect the unit in the test stations, then go and keep working on debug, and if a unit finishes its test, the operator will stop debugging again to go and transport that unit to Debug WIP or to the next process depending on the yield and so on... The main priority for the operator is the test stations utilization maximized, we trying to prove more than 1 operator is needed to also keep debug in control.

Thank you in advance,

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Joshua S Luis T7 commented · Feb 13, 2019 at 10:35 PM

Should there be a queue next to the debugging station for all the other parts that will build up next to it that were sent to be debugged as well?

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Luis T7 Joshua S commented · Feb 13, 2019 at 10:42 PM

@Joshua S

Yes, the model is constructed this way:

1 source -- arrivals random for the moment

1 Queue for raw material - if test stations are full then Inventory is going to start to increment

3 test stations - All of them have the same time and the same yield 80% pass 20% Fail

1 Queue for DEBUG WIP - if operator is busy then the process will be paused until operator can finish the process and star processing the next unit on the queue.

1 Debug Station - Operator needed to debug the unit

1 Operator

1 Sink

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Answer 1 · 2019-02-15T21:22:27Z

Jeff Nordgren answered Feb 15, '19 Luis T7 commented Feb 18, '19

@Luis T7,

Attached is you model with the changes that I've made. The best way I was able to figure out how to do what you are wanting to do is to use Process Flow.

The model flow should be like this: If there is a flowitem in IPK and a free Processor, the Operator will load the flowitem from IPK and take it to the open Processor AND will wait for the Processor to finish its Setup Time. When a flowitem has finished processing in one of the Processors, the Operator will go to that Processor, load the flowitem and take it to either the Next_Process or to the WIP_Debug queue.

The "Main Flow" of the model is the debugging process. That is because when that flow is going on, it can be preempted away from that process. So, the Main Flow is the "processing" that will be preempted, in the model, not the Testing process. I hope that makes sense? What it boils down to really is that when the Debug processor is processing, it can be preempted by anything needed to be done in the Testing area.

Also I noticed that your Source was creating flowitems ever 5 time units. With that being the case, there is hardly a time when the Testing area doesn't need attention. And because it preempts the processing of Debug, the flowitem in Debug takes forever to process or never will. So I set the Source to produce a flowitem every 35 time units. This way you can actually see the order of things happening in the model.

Take a look at the model and see if it is doing what you are wanting it to do. If not, please explain further what needs to change.

Thanks.

sn-resource-priorities-jn2.fsm

sn-resource-priorities-jn2.fsm (52.5 KiB)

· 1

Luis T7 commented · Feb 18, 2019 at 09:18 PM

Thank you @Jeff Nordgren!, it does exactly what I was trying to do.

Regards,

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