This new feature is great because it allows simulation users to get that level of detail
and accuracy that's required to make a system reflect reality.
Let’s take a look at the new overtime feature in SIMUL8 2016.
This feature can be used to extend the working hours of the day to help ensure that
all vital work in the simulation has been processed.
We’ll start with this example simulation.
First off, double click the on-screen clock to see the clock properties.
So, as you can see, we’re running our simulation for 8 hours a day starting at 9am.
There’s now a new option here allowing you to extend the day with overtime.
If I check this box, there is an option to add a maximum amount of time that the day should be extended by.
In this example we are running in minutes and want to extend the day by 2 hours or 120 minutes.
But first, let’s run the simulation to see what happens when overtime is not enabled.
The start point will generate items based on distribution; those items will then wait
in queues until processed by the activities. In this example the working day ends at exactly
5pm. At this point the simulation will jump to the start time of the next day including
work in the system that hasn’t been processed the day before.
So, let’s go ahead and add in some overtime to this example.
If we go back into the clock properties we can go ahead and check the box to ‘Extend with Overtime’
and use a period of 120 minutes – or 2 hours.
Now, the first thing you might notice is the clock resets to midnight and is now red which
indicates that overtime is enabled in the simulation.
If I just step through the simulation you’ll see that the first event is
the clock jumping to 9am - the start of the working day.
Let’s run the simulation again to see what happens when overtime is enabled.
Again, items go through as intended but, at 5pm, overtime will extend the day. It will
change to overtime for the two hours we set and the clock will turn red.
When the simulation is in the overtime period, any Start Points cease to create arrivals,
however all other objects continue to process work items for the duration of the overtime period.
Only the work items currently in the system are being processed in the activities.
Of course this doesn’t mean that it will clear the entire system – that depends on the length of overtime.
However, what it does allow your system to do is ‘catch up’ so it can
try to process as many items within an extended time frame.
If we run the simulation to the end I can show you the new overtime results
which are available to analyse.
Let’s go into this activity and select it’s results. You will notice there is a new option
at the bottom to choose the time that we want to look at. Normal time represents the regular
working day – in this case, 9am until 5pm.
We can choose to focus on the overtime results or we can choose to look at the results for
both periods combined.
These results are available on the activities, on the queues and even on resources.
The overtime feature also allows additional functionality in the activity routing in properties.
If I select this activity, go to the routing in option and choose the options tab, there
are now two new options here. This will allow you to control what the activity routes in
during overtime, if anything at all.
The first option is ‘During Overtime’. This allows you to set which activity will
not select any work when the overtime period has occurred. The second option is ‘Blocked
during normal time’. This allows you to set an activity to process items during an
overtime period only.
This great feature adds lots of flexibility to simulations.
For example, if you’re working in a medical clinic you may want to ensure that the system
is seeing as many patients as it can, even if the day has ended.
Or another example is if you are in manufacturing you may want to look at how much overtime
you will need in order to get your desired throughput.