Time-Step Query

[vensimuser82939]

Hi,

I have a stock and flow diagram. I have an inflow in terms of calls/month which flows into a stock (calls waiting to be responded to) in unit terms of 'calls'. In order for unitary equalisation I would like to have the stock in terms of month. Potentially looking at how to clear the backlog.

[tomfid]

I think you want to leave the stock units alone, and handle it a bit differently. Something like:

Overdue calls = INTEG( ... ) ~ calls
Desired call rate = new call arrival rate + overdue calls/time to catch up ~ calls/month
Desired staff = Desired call rate / Productivity ~ people
Productivity = ... ~ calls/person/month
Time to catch up = ... ~ month ~ represents the normal time over which the call backlog will be cleared

[vensimuser82939]

Hi Tom,

Thanks for your reply - really helpful this is in relationship to the thread "hire fire policy model query". One question I have is in regards to the "Time to catch up". What would you recommend? They currently have 25 staff each capable of completing 120 calls a month. The model starts with 3,000 calls flowing in so the backlog will be the responsibility of new staff only.

The model runs for 48 months. Is this "Time to Catch Up" something a manager could determine - eg. how urgent does he want the backlog removed?

[Administrator]

The model runs for 48 months. Is this "Time to Catch Up" something a manager could determine - eg. how urgent does he want the backlog removed?

Correct. If the manager wants all service requests cleared immediately, then obviously the time to remove the backlog needs to be short (which means more staff and more costs).

so the backlog will be the responsibility of new staff only

I'd be surprised if any company placed my service request into a backlog and recruited some staff to deal with it. Why not just call again and again to try and get through to someone who would service the call immediately?

[vensimuser82939]

Hi, this relates to the other recent post. It surrounds service requests so their request for support is overdue. I understand it's sometimes beneficial to 'SMOOTH' inflows when calculating things such as the desired call rate / desired staff rate. Would you recommend I smoothed the inflowing new calls/requests for support over a couple of months?

The model runs for 48 months. Is this "Time to Catch Up" something a manager could determine - eg. how urgent does he want the backlog removed?

Correct. If the manager wants all service requests cleared immediately, then obviously the time to remove the backlog needs to be short (which means more staff and more costs).

so the backlog will be the responsibility of new staff only

I'd be surprised if any company placed my service request into a backlog and recruited some staff to deal with it. Why not just call again and again to try and get through to someone who would service the call immediately?

[Administrator]

Would you recommend I smoothed the inflowing new calls/requests for support over a couple of months?

I think that is probably what I would do.