INVENTORIES

As of the dates indicated, inventories are comprised of the following (in thousands):



	April 30, 2018			October 31, 2017
Raw materials	$	48,356		$	52,898
Work-in-process	13,253			18,623
Finished goods	165,733			185,488
Deferred cost of goods sold	55,161			61,340
	282,503			318,349
Provision for excess and obsolescence	(51,165		)	(51,206		)
	$	231,338		$	267,143

Ciena writes down its inventory for estimated obsolescence or unmarketable inventory by an amount equal to the difference between the cost of inventory and the estimated net realizable value based on assumptions about future demand and market conditions. During the first six months of fiscal 2018, Ciena recorded a provision for excess and obsolescence of $15.0 million, primarily related to a decrease in the forecasted demand for certain Networking Platforms products. Deductions from the provision for excess and obsolete inventory relate primarily to disposal activities.