13-08-2019, 01:06 AM

I have been trying to recreate the TIMES OBJINV calculation for processes with lead times.

The process in question has TLIFE=40, ELIFE=30 and ILED=-5. The model base year is 2010 and the periods are 2010, 2011, 2012, 2013-2017, 2018-2022, further 5-year periods.

I've calculated OBJINV coeffs for 2011 and 2020 vintages. See the attached workbook for the discount rates and calculation.

For 2020, I can almost recreate the TIMES calculation (I'd be interested to know the cause of the 0.05% error, but am not worrying about it).

For 2011, when the lead time would be prior to the base year, I can't recreate the TIMES calculation. Do you know what I'm doing incorrectly?

The process in question has TLIFE=40, ELIFE=30 and ILED=-5. The model base year is 2010 and the periods are 2010, 2011, 2012, 2013-2017, 2018-2022, further 5-year periods.

I've calculated OBJINV coeffs for 2011 and 2020 vintages. See the attached workbook for the discount rates and calculation.

For 2020, I can almost recreate the TIMES calculation (I'd be interested to know the cause of the 0.05% error, but am not worrying about it).

For 2011, when the lead time would be prior to the base year, I can't recreate the TIMES calculation. Do you know what I'm doing incorrectly?