Operating cash conversion

Could someone please answer this simple question about the industry in which CTD and WEB operate. 

Can CTD and WEB both realistically achieve 100% cash conversion (or thereabouts) by year end, when the half year results suggest otherwise?

Consider the following about each.
CTD
For FY18, OCF was $94.4m, compared with $69.3m for FY17. Good result if CTD was not deferring cash payments to suppliers at 30/6/18.
As the AFR's "Rear window" points out this morning, cash flow for 1H19 fell to $14.1m from $25.7m (for 1H18), yet management said "the timing of the cycle will completely reverse at 30 June 2019 and the group expects circa 100% operating cash conversion for the full year". VGI thinks CTD has a problem and now Rear Window is using the latest result to point the finger of suspicion.
WEB
For FY18, OCF was $120.8m, compared with $34.8m for FY17. Cash flow boosted by JacTravel?
For 1H19, OCR was NEGATIVE $26.2m, compared to NEGATIVE $14.5m for 1H18.
So WEB achieved 100% cash conversion for FY18, but can they do it again in FY19?. 
 
Just asking.