Product Warranties

9 Months Ended

Jun. 30, 2018

Guarantees and Product Warranties [Abstract]

Product warranties

Product Warranties

The Company accrues warranty obligations associated with certain products as revenue is recognized. Provisions for the warranty obligations are based upon historical experience of costs incurred for such obligations, adjusted for site‑specific risk factors, and, as necessary, for current conditions and factors. There are significant uncertainties and judgments involved in estimating warranty obligations, including changing product designs, differences in customer installation processes and future claims experience which may vary from historical claims experience.

A reconciliation of the activity related to the accrued warranty, including both the current and long‑term portions, is as follows:

	Nine Months Ended June 30,
	2017		2018
Balance at beginning of the period	$	23,309	$	17,274
Warranty provision for sales	4,108		2,697
Settlement of warranty claims	(9,701)		(8,221)
Foreign currency translation and other	(341)		(445)
Balance at end of the period	$	17,375	$	11,305

The decline in accrued warranty over the periods presented is attributable to improved product quality and better project execution, as well as the expiration of warranty periods for certain specific exposures related to discontinued products.