Open question: Supply: Why does Wacholderbusch (JNPR) have 0 inventory?

In a research work on Cisco (CSCO) for my university financial category writing. I compare Cisco with the following highest market share company the Wacholderbusch (JNPR). If I regard the balance after Wacholderbusch, he explains: The Warenbestand-Umsatz-Verhältnis-0 inventory/sales of the daily Warenbestand-des Umsatz-0.0 0,0 the ranges, which I compare, is liquidity ratio, cheapness multiplier, inventory conversion, ROA and PET conditions. I do not have a way of comparing the inventory conversion, since he is 0. Which possible reasons for this are. Owing to!!