Need help with Report for Lag Forecast

Question

Hi All,
I need your inputs in creating a Report to show Lag Forecast.
Forecast is done on a weekly basis. Assuming forecast is done at a time for 3 upcoming weeks, the data in the cube will be as follows:
ZCALWEEK     CALWEEK     MATERIAL     FORECAST
46     47     ABC     2
46     48     ABC     3
46     49     ABC     6
47     48     ABC     11
47     49     ABC     8
47     50     ABC     14
48     49     ABC     10
48     50     ABC     2
48     51     ABC     5
49     50     ABC     4
49     51     ABC     6
49     52     ABC     9
Now the calculation for lag is as follows:
Lag1 for Week 47 = Forecast for Week 47 done in ZCALWEEK 46
Lag2 for Week 47 = Forecast for Week 47 done in ZCALWEEK 45
Lag2 for Week 48 = Forecast for Week 48 done in ZCALWEEK 46
User wants to run the Report for a range of Calweeks.
For the Selection -  Calweek: 47-49 Report should be as follows:
CALWEEK     47          48          49     
Material     LAG1     LAG2     LAG1     LAG2     LAG1     LAG2
ABC     2          11     3     10     8
To achieve this we used the variable for Calweek and offset its value.
So Lag 1 = Forecast restricted by week 47-1
Lag 2 = Forecast restricted by week 47-2
This approach of offsetting variable only works for the first week that is week 47.
In the subsequent weeks the value is offset again to the same value as first week.
For example in Lag2 for Week 49 = Forecast for Week 49 done in ZCALWEEK 47. However the offset approach fetches value of the Forecast done in week 45.
Please advice as to how this might be solved.
Is it possible to show the Report for a range of weeks or is it only feasible to show data for one week at a time?
Thanks in Advance,
Amrita

Answer 1

Create an user entry variable that computes the current lag and create replacement path variables replaced by the selection variable and the current offsets. Have you tried this approach?
If this replacement path variable approach not working you can try calculation everything using formulas in transformations that can directly input required lags in cube itself.