11. Share-Based Compensation

CRA recorded approximately $6.5 million, $6.7 million, and $5.8 million of compensation expense for fiscal 2017, fiscal 2016, and fiscal 2015, respectively, for share-based awards consisting of stock options, shares of restricted stock, time-vesting restricted stock units, and performance-vesting restricted stock units issued to employees and directors based on their respective estimated grant date fair values. Performance-vesting restricted stock units are expensed using the graded acceleration method.

In addition, CRA recorded $127,000, $146,000, and $11,000 of share-based compensation expense during fiscal 2017, fiscal 2016, and fiscal 2015, respectively, for share-based awards consisting of stock options and shares of restricted stock issued to non-employees (other than directors).

Share-based Compensation Plans. As of December 30, 2017, CRA's active equity-based compensation plans consist of its Amended and Restated 2006 Equity Incentive Plan, as amended (the "2006 Equity Plan"), and its 1998 Employee Stock Purchase Plan (the "1998 ESPP"), a tax-qualified plan under Section 423 of the Internal Revenue Code. During fiscal 2009, CRA also implemented a long-term incentive program, or "LTIP," as a framework for grants made under the 2006 Equity Plan to its senior corporate leaders, practice leaders and key revenue generators. Under the LTIP, participants have received a mixture of stock options, time-vesting restricted stock units, and performance-vesting restricted stock units in each fiscal year since 2009, except 2012. In December 2016, CRA's board of directors amended CRA's Cash Incentive Plan to facilitate the grant to LTIP participants of service-based and performance-based cash awards as a component of the LTIP. The LTIP is designed to reward CRA's senior corporate leaders, practice leaders and key revenue generators and provide them with the opportunity to share in the long-term growth of CRA.

2006 Equity Plan: Maximum and Available Shares. The 2006 Equity Plan authorizes the grant of a variety of incentive and performance awards to CRA's directors, employees and independent contractors, including stock options, shares of restricted stock, restricted stock units, and other equity awards. The 2006 Equity Plan has used standard "fungibility ratios" to count grants of full-share awards (such as shares of restricted stock and restricted stock units) against the maximum number shares issuable under the plan. The current fungibility ratio, applicable to grants made on or after April 30, 2010, is 1.83. The fungibility ratio does not apply to grants of stock options. The maximum number of shares issuable under the 2006 Equity Plan is 5,274,000, consisting of (1) 500,000 shares initially reserved for issuance under the 2006 Equity Plan, (2) 1,000,000 shares that either remained for future awards under CRA's 1998 Incentive and Nonqualified Stock Option Plan (the "1998 Option Plan") on April 21, 2006, the date CRA's shareholders initially approved the 2006 Equity Plan, or were subject to stock options issued under the 1998 Option Plan that were forfeited or terminated after April 21, 2006, (3) 210,000 shares approved by CRA's shareholders in 2008, (4) 1,464,000 shares approved by CRA's shareholders in 2010, (5) 2,500,000 shares approved by CRA's shareholders in 2012 reduced by the 800,000 shares cancelled by CRA's board of directors on April 22, 2016, and (6) the 400,000 shares approved by CRA's shareholders on July 12, 2017. The shares available for grant under the 2006 Equity Plan as of December 30, 2017 was 434,374.

1998 Option Plan. With the adoption of the 2006 Equity Incentive Plan in 2006, CRA stopped granting awards under the 1998 Option Plan, and, as of December 30, 2017, there were no awards outstanding under the 1998 Option Plan.

Stock Options. A summary of option activity during fiscal 2017 from the 2006 Equity Plan is as follows. The awards granted under the 1998 Option Plan all expired prior to December 30, 2017 and, as noted above, no awards were granted under the 1998 Option Plan during fiscal 2017. Accordingly, all of the stock options outstanding as of December 30, 2017 were granted under the 2006 Equity Plan.

	Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
								(in thousands)
Outstanding at December 31, 2016		945,083		$	22.95
Fiscal 2017:
Granted		22,757			44.87
Exercised		(293,439	)		21.88			$	5,372
Expired		—			—
Forfeited		(8,684	)		24.58

Outstanding at December 30, 2017		665,717			24.14		4.00	$	13,851


Options exercisable at December 30, 2017		456,639		$	22.78		3.39	$	10,123


Vested or expected to vest at December 30, 2017		663,088		$	24.13		4.00	$	13,802

The weighted average fair market value using the Black-Scholes option-pricing model of the stock options granted under the 2006 Equity Incentive Plan in fiscal 2017, fiscal 2016 and fiscal 2015 was $11.54, $9.93 and $7.37, respectively. The fair market value of the stock options at the date of grant was estimated using the Black-Scholes option-pricing model with the following weighted average assumptions:

	2017			2016			2015
Risk-free interest rate		2.1	%		1.3	%		1.4	%
Expected volatility		32	%		36	%		39	%
Expected dividend yield		1.5	%		1.5	%		—
Forfeiture rate		0.4	%		0.5	%		1.1	%
Weighted average expected life (in years)		4.49			4.58			4.50

The risk-free interest rate is based on U.S. Treasury interest rates with corresponding terms consistent with the expected life of the stock options. Expected volatility and expected life are based on CRA's historical experience. Expected dividend yield was determined based on CRA's annualized dividend rate per share, as a percentage of average market price of the common stock, on each dividend payment date. The forfeiture rate used was based upon historical experience. CRA believes its historical experience is an appropriate indicator of future forfeitures.

The aggregate intrinsic value of stock options exercised in fiscal 2017, fiscal 2016, and fiscal 2015 was approximately $5.4 million, $0.7 million, and $0.1 million, respectively. The following table summarizes stock options outstanding and stock options exercisable as of December 30, 2017:

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Number Outstanding at December 30, 2017		Weighted-Average Remaining Contractual Life (years)		Weighted-Average Exercise Price		Number Exercisable at December 30, 2017		Weighted-Average Remaining Contractual Life (years)		Weighted- Average Exercise Price
$16.12 - 21.48		181,630		2.89	$	18.48		181,630		2.89	$	18.48
$21.49 - 26.86		276,737		4.07		21.60		158,035		3.48		21.66
$26.87 - 32.23		184,593		4.25		30.98		116,974		4.04		30.98
$42.98 - 48.35		22,757		9.97		44.87		—		—		—

Total		665,717		4.00	$	24.14		456,639		3.39	$	22.78

The following table provides a roll-forward of the outstanding non-vested stock options over fiscal 2017:

	Options
	Number of Shares			Weighted-Average Fair Value
Non-vested at December 31, 2016		367,120		$	8.74
Granted		22,757			11.54
Vested		(172,115	)		8.80
Forfeited		(8,684	)		8.95

Non-vested at December 30, 2017		209,078		$	8.98

The total fair value of stock options that vested during fiscal 2017, fiscal 2016, and fiscal 2015 was $1.5 million, $1.5 million, and $1.5 million, respectively. As of December 30, 2017, there was $1.7 million of total unrecognized compensation cost, net of expected forfeitures, related to non-vested stock options granted. That cost is expected to be recognized over a weighted-average period of 2.0 years.

Restricted Stock. CRA grants shares of restricted stock, which are subject to the execution of a restricted stock agreement, under its 2006 Equity Incentive Plan. Generally, shares of restricted stock vest in four equal annual installments beginning on the first anniversary of the date of grant. Total unrecognized compensation cost, net of expected forfeitures, related to shares of restricted stock as of December 30, 2017 was $0.9 million, which is expected to be recognized over a weighted-average period of 2.7 years. The forfeiture rate of 0.9% used for shares of restricted stock was based upon historical experience. CRA believes its historical experience is an appropriate indicator of future forfeitures.

The following table provides a roll-forward of the shares of restricted stock under the 2006 Equity Incentive Plan over fiscal 2017:

	Shares of Restricted Stock
	Number of Shares			Weighted-Average Fair Value
Non-vested at December 31, 2016		62,122		$	23.64
Granted		16,494			36.36
Vested		(25,891	)		22.93
Forfeited		—			—

Non-vested at December 30, 2017		52,725		$	27.97

The total fair value of shares of restricted stock that vested during fiscal 2017, fiscal 2016, and fiscal 2015 was $0.6 million, $0.6 million, and $0.6 million, respectively.

Time-Vesting RSUs. CRA grants time-vesting restricted stock units, which are subject to the execution of a restricted stock unit agreement, under its 2006 Equity Incentive Plan. Generally, time-vesting restricted stock units vest in four equal annual installments beginning on the first anniversary of the date of grant. Total unrecognized compensation cost, net of expected forfeitures, related to time-vesting restricted stock units as of December 30, 2017 was $2.9 million, which is expected to be recognized over a weighted-average period of 2.3 years. The forfeiture rate of 0.9% used for time-vesting restricted stock units was based upon historical experience. CRA believes its historical experience is an appropriate indicator of future forfeitures.

The following table provides a roll-forward of the time-vesting restricted stock units under the 2006 Equity Incentive Plan over fiscal 2017:

	Time-Vesting Restricted Stock Units
	Number of Units			Weighted-Average Fair Value
Non-vested at December 31, 2016		184,751		$	24.18
Granted		25,958			38.38
Vested		(86,547	)		23.27
Forfeited		(4,342	)		24.58

Non-vested at December 30, 2017		119,820		$	27.90

The total fair value of time-vesting restricted stock units that vested during fiscal 2017, fiscal 2016, and fiscal 2015 was $2.0 million, $1.9 million, and $1.8 million, respectively.

Performance-Vesting RSUs. CRA grants performance-vesting restricted stock units ("PRSUs"), which are subject to the execution of a restricted stock unit agreement, under its 2006 Equity Incentive Plan. Generally, achievement of performance measures for PRSUs are based on a two year performance period, after which the units determined based on this achievement will vest three-fourths in the first year following the performance period and one-fourth on the fourth anniversary of the date of grant. The number of units determined based on the achievement of a PRSUs performance measures generally ranges from 50% to 125% of the PRSU's target number of units.

In accordance with ASC Topic 718, for PRSUs awarded to employees, CRA estimates share-based compensation cost at the grant date based on the fair value of the award and recognizes the cost over the requisite service period using the graded acceleration method.

The following table provides a roll-forward of the performance-vesting restricted stock units under the 2006 Equity Incentive Plan over fiscal 2015, fiscal 2016 and fiscal 2017. For purposes of this table, granted PRSUs are counted based on the maximum number of units that could vest upon achievement of the PRSUs' performance conditions which, for all periods presented, equaled 125% of the PRSU's target number of units.

	Performance-Vesting Restricted Stock Units
	Number of Units
Non-vested at January 3, 2015		365,468
Granted		204,315
Vested		—
Forfeited		(11,624	)

Non-vested at January 2, 2016		558,159


Granted		26,666
Vested		(90,485	)
Forfeited		(83,187	)

Non-vested at December 31, 2016		411,153


Granted		32,721
Vested		(98,882	)
Forfeited		(64,397	)

Non-vested at December 30, 2017		280,595

1998 ESPP. In fiscal 1998, CRA adopted the 1998 ESPP, a tax-qualified plan under Section 423 of the Internal Revenue Code. The 1998 ESPP authorizes the issuance of up to an aggregate of 243,000 shares of common stock to participating employees at a purchase price equal to 85% of fair market value on either the first or the last day of the one-year offering period under the plan. In fiscal 2017, fiscal 2016, and fiscal 2015, there were no offering periods under this plan and no shares were issued. As of December 30, 2017, 211,777 shares are available for grant under the 1998 ESPP.

Other Equity Matters. During fiscal 2017, CRA modified certain restricted stock awards in connection with a director's retirement to eliminate the forfeiture of unvested shares upon his retirement and to permit the time-based vesting to continue despite such retirement. The modification resulted in total additional compensation cost of $0.3 million.