Change operator when the shift changes on a custom fixed resource.

Question

question

Kari Payton asked Aug 10 2016 at 2:29 PM Adrian Haws commented Aug 15 2016 at 9:50 PM

Change operator when the shift changes on a custom fixed resource.

I'm trying to use shift schedules to set operator hours. The problem is that the operators don't stop and switch out when their shift ends. The first group of operators leave after their 12 hour shift but the second group doesn't come in to finish the task. My operators are grouped as a resource. Maybe this is not the best way to model using operators for a custom fixed resource process.

shifts.fsm

Software Version:

FlexSim 16.1.2

time table shift schedule fixed resource process flow process flow preemption

shifts.fsm (45.1 KiB)

· 2

Kari Payton commented · Aug 12 2016 at 1:40 PM

@Matt Long @Adrian Haws hey thanks for the answers. I attempted to use preemption, but still struggling with it. Please help if you can. I attached the model. The operators are not being released from their tasks even though they are going on off shift. preemption-shift-workers.fsm

0 ·

preemption-shift-workers.fsm (29.8 KiB)

Adrian Haws Kari Payton commented · Aug 15 2016 at 9:50 PM

@Kari Payton I'm not sure exactly what you're trying to do with the preemption, but I've made a few small changes in your model.

First, you have to make sure that the resource you're trying to utilize is actually acquired. In your model you release the resource, but didn't acquire a new one before calling tasks like "Travel", "Change Visual", etc, with a reference to the "resource" label. What I did was to release that resource, then immediately acquire a new one. (As a side note, I made sure to not acquire the resource I just released by using a query).

Second, when the source for preempting creates a new token, there isn't always a token in the "Delay" activity to assign to the label "preemptedTokens". Therefore I made a "Decide" activity see if that label exists, and if it doesn't to send it to a sink.

See attached model.

0 ·

1881-preemption-shift-workers-2-1.fsm (30.6 KiB)

______

Cookie preferences

Your privacy is important to us and so is an optimal experience. To help us customize information and build applications, we collect data about your use of this site.

May we collect and use your data?

Learn more about the Third Party Services we use and our Privacy Statement.

Strictly necessary – required for our site to work and to provide services to you

These cookies allow us to record your preferences or login information, respond to your requests or fulfill items in your shopping cart.

YES

Improve your experience – allows us to show you what is relevant to you

These cookies enable us to provide enhanced functionality and personalization. They may be set by us or by third party providers whose services we use to deliver information and experiences tailored to you. If you do not allow these cookies, some or all of these services may not be available for you.

YES

NO

Customize your advertising – permits us to offer targeted advertising to you

These cookies collect data about you based on your activities and interests in order to show you relevant ads and to track effectiveness. By collecting this data, the ads you see will be more tailored to your interests. If you do not allow these cookies, you will experience less targeted advertising.

YES

NO

Are you sure you want a less customized experience?

We can access your data only if you select "yes" for the categories on the previous screen. This lets us tailor our marketing so that it's more relevant for you. You can change your settings at any time by visiting our privacy statement

Your experience. Your choice.

We care about your privacy. The data we collect helps us understand how you use our products, what information you might be interested in, and what we can improve to make your engagement with Autodesk more rewarding.

May we collect and use your data to tailor your experience?

Explore the benefits of a customized experience by managing your privacy settings for this site or visit our Privacy Statement to learn more about your options.

Answer 1 · 2016-08-10T15:17:03Z

Matt Long answered Aug 10 2016 at 3:17 PM Adrian Haws commented Aug 11 2016 at 6:29 PM

The issue specifically with your model is the first two operator tokens get stuck in the Delay activity because your Time Table preempts the operators to travel to the cylinder and then tells them to delay until their next shift.

There are probably multiple ways to handle this, but when it comes to schedules and dealing with Time Tables, I would recommend taking a look at the Preemption activities. Save Token Context, Release Token and Restore Token Context. The User Manual has a few examples of how to use these activities.

In the attached model I added an Event-Triggered Source for each time table listening to their Down Function. I then call Release Token on the tokens sitting in the Delay activity. This gets the tokens moving, but it still doesn't completely solve the problem.

The problem is in the disconnect between the Time Table and Process Flow. The Resource doesn't perform any checks as to whether an operator is "off shift" or not. It doesn't know anything about Time Tables or MTBF/MTTR objects. You have to manually control the Process Flow in these situations.

Without any additional changes to the model, the Operator's are acquired before they have finished their "off shift" time (7AM). This is due to the second shift's delay only being 11 hours and finishing before the next shift is scheduled to start. You'll probably wan to perform some checks to see if your operators are on shift before acquiring. One way of doing this would be to have some Event-Triggered Sources or Wait for Events set up to listen to the Time Tables and perform appropriate actions depending on their state.

shifts-updated.fsm

shifts-updated.fsm (47.5 KiB)

· 3

Kari Payton commented · Aug 11 2016 at 5:47 PM

@Matt Long @Adrian Haws I read the help manual about Preemption and have a little better understanding of it. However, in the model I don't want the operators on the first shift to pick back up where they left off. I want the operators on the 2nd shift to pick up where the first shift left off.

The first process takes 14 hours, but the operators are on a 12 hour shift. So I want the operators that come in on the second shift to finish the last two hours of processing that the first shift didn't get to.

0 ·

Adrian Haws Kari Payton commented · Aug 11 2016 at 6:29 PM

@Kari Payton This answer talks about how to do this.

1 ·

Matt Long Kari Payton commented · Aug 11 2016 at 6:27 PM

The task sequence activities don't save any info when you use the Save Context activity. So it may be best to use a Delay activity for the processing time. Then when the operators go off shift, you want to save the context of the tokens in the Delay and release them to a block of activities that will release their current operators and acquire new operators. Once the new operators get to the point where they need to finish processing, you restore the context of the token back to the delay activity.

0 ·

Answer 2 · 2016-08-10T14:57:45Z

Adrian Haws answered Aug 10 2016 at 2:57 PM Adrian Haws edited Aug 10 2016 at 3:46 PM

There are different ways of going about this. This answer has a model with two operators switching off using a MTBF MTTR table and a Fixed Resource Process Flow. 1484-901-shift-tests.fsm

You might also be interested in the model from this answer. 1096-process-flow-schedule-1.fsm

I see that you're using time tables in your model, which works fine. It looks like the thing that's not allowing your two available operators to be acquired is that you can't get to the second "Run Sub Flow" activity until the first one is done. You'll want to set up your logic just a little bit differently. I can't say whether or not this works how you'd like your model to, but I attached a revised version of your model that allows for all operators to be acquired. 1836-shifts-1.fsm

1484-901-shift-tests.fsm (52.3 KiB)

1096-process-flow-schedule-1.fsm (22.5 KiB)

1836-shifts-1.fsm (46.0 KiB)

question