Note 9. Accrued Liabilities

Accrued liabilities as of April 30, 2018 and October 31, 2017 consisted of the following:

	April 30,		October 31,
	2018		2017
Accrued payroll and employee benefits	$	3,124	$	5,315
Accrued contract loss		—		37
Accrued product warranty cost ⁽¹⁾		343		348
Accrued material purchases⁽²⁾		548		2,396
Accrued service agreement costs⁽³⁾		1,726		3,319
Contractual milestone billings for inventory⁽⁴⁾		5,921		4,440
Accrued legal, taxes, professional and other		3,069		2,526
Accrued liabilities	$	14,731	$	18,381

(1)

Activity in the accrued product warranty costs for the six months ended April 30, 2018 included additions for estimates of future warranty obligations of $0.3 million on contracts in the warranty period and reductions related to actual warranty spend of $0.3 million as contracts progress through the warranty period or are beyond the warranty period.

(2)

The Company acts as a procurement agent for POSCO Energy under an Integrated Global Supply Chain Agreement whereby the Company procures materials on POSCO Energy’s behalf for its Korean production facility. This liability represents amounts received for the purchase of materials on behalf of POSCO Energy. Amounts due to vendors is recorded as “Accounts payable.”

(3)

The loss accruals on service contracts were $1.1 million as of October 31, 2017 which decreased to $1.0 million as of April 30, 2018. The accruals for performance guarantees decreased from $2.2 million as of October 31, 2017 to $0.7 million as of April 30, 2018 resulting from payments offset by additional accruals for the minimum power output falling below the contract requirements for certain service agreements.

(4)	Amounts represent contractual milestone billings for inventory that will be provided to POSCO Energy within the next twelve months under a transaction that will not result in revenue recognition.