What is the difference between activity and event in "simulation"?

[shivajikobardan]

I am studying about components of a system.

Activity-:

It is What entities do to cause changes is activity. It is represented by time period of a specified length.

Event-:

Event is defined as an instantaneous occurrence that might change state of the system. Endogenous events occurs within the system and exogenous events occurs outside the system.

eg-: making a deposit is an activity, arrival of customer is an exogenous event and completion of service of a customer is an endogenous event.

I don't see any difference between them. making deposits can also be an event as it'll change the state of the system. i.e money in bank account.

The one difference that can be taken from these definitions is "instantaneous" vs "time period' but the examples don't deliver anything about it.

Below is the figure from a slide available online.

https://lh4.googleusercontent.com/chMzYhlTlQxQnffh5UfK6qQZTl10HyYnUBBh0j4PiyTeF7A7_-qi1qxsr9on4Rvp6iUiMkz_haHmoPJUdVeybaWkhtwhWsGBFGrxDjiXqCW9mEguaVfdXMs259fd1Y7ziXJU_GMA4ydvMOxJ2e_kM4I

 

[whartung]

An activity, for lack of a better word, takes time. Getting the burger from the counter is an event, but eating it is an activity. Ordering is an activity. Talking with the wait staff, "you want fries with that", etc. Once you've finished Ordering, an Order is Placed. That's an event. The order is now in the kitchen where it can be prepared (another activity). But the Order Placed is the event that triggered that activity.

Once you've eaten (activity), you go to Pay. Paying is an activity (cash or card, sign here, etc.), but at some point you will move from "owing" to "paid". That's an event that triggered that state.

If you Exit (an event) but are still "Owing", then the "Bouncer" activity starts as someone runs out to catch you.

 

[.Scott]

"Making a Deposit" is not an event. The events might be "New deposit record is available", "start of deposit creation", "deposit envelope received", "new deposit record serial number ready", etc. There may be dozens of milestone events that occur in the process of "making a deposit".