i really didn't know how to set up a lookup function/
i have try it ,but still didn't work
hope some one can help me
thank you ..
if i want to set up that demand is a lookup of price.
how to do it?
lookup ? how to use it
lookup ? how to use it
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There are some basic errors in your look-up formulation.
1. You have not normalized your lookups. By normalizing, I mean you want to generate an 'effect' of price on 'demand'. The units for price would be 'dollars / chip'. The units for demand would be 'chips / day'. So the two units do not match. You are comparing apples and oranges.
2. I notice that your table function is hump shaped. This is a wrong formulation of the lookup. Lookups need to be either monotonically increasing or decreasing
A couple of other errors not related to your lookups
3. The formulation for 'sales' is not robust. Your inventory could become negative - and hence sales
4. You have chosen the wrong time-step. Your delivery time is 1. And the time step you have chosen is also 1. This is going to give you wrong results
To get some information on all the above, will strongly recommend to you to read a text like John Sterman's Business Dynamics - before attempting to make SD models.
Malli
1. You have not normalized your lookups. By normalizing, I mean you want to generate an 'effect' of price on 'demand'. The units for price would be 'dollars / chip'. The units for demand would be 'chips / day'. So the two units do not match. You are comparing apples and oranges.
2. I notice that your table function is hump shaped. This is a wrong formulation of the lookup. Lookups need to be either monotonically increasing or decreasing
A couple of other errors not related to your lookups
3. The formulation for 'sales' is not robust. Your inventory could become negative - and hence sales
4. You have chosen the wrong time-step. Your delivery time is 1. And the time step you have chosen is also 1. This is going to give you wrong results
To get some information on all the above, will strongly recommend to you to read a text like John Sterman's Business Dynamics - before attempting to make SD models.
Malli