ACV, or Annual Contract Value, is a financial performance metric that we introduced in 2018. We believe this new measure is an improved metric as compared to the historically provided bookings metric because it adjusts the sales bookings metric to reflect only the annual value of a contract and also adjusts to reflect the sales booking at the date of the contract inception or renewal. There is no GAAP measure comparable to ACV. ACV is composed of the following:

• the annualized value of maintenance and lease contracts with start dates or anniversary dates during the period, plus
• the value of perpetual license contracts with start dates during the period, plus
• the annualized value of fixed-term services contracts with start dates or anniversary dates during the period, plus
• the value of work performed during the period on fixed-deliverable services contracts.

Management's 2019 Financial Outlook

The Company's first quarter and fiscal year 2019 revenue and diluted earnings per share guidance is provided below. The revenue and diluted earnings per share guidance are provided on both a GAAP and a non-GAAP basis, in accordance with ASC 606. Non-GAAP financial measures exclude the income statement effects of acquisition adjustments to deferred revenue, stock-based compensation, amortization of acquired intangible assets and acquisition-related transaction costs.

The financial guidance below includes the impact of the Company's acquisitions of Granta and Helic, which closed during the first quarter of 2019.

First Quarter 2019 Guidance

The Company currently expects the following for the quarter ending March 31, 2019:

Fiscal Year 2019 Guidance

The Company currently expects the following for the fiscal year ending December 31, 2019:

During Q1 2019, we acquired Granta and Helic for a combined purchase price of approximately $261.5 million. The acquisition of Granta, the premier provider of materials information technology, expands the Company's portfolio into this important area, giving customers access to material intelligence, including data that is critical to successful simulations. The acquisition of Helic, the industry-leading provider of electromagnetic crosstalk solutions for systems on chips, combined with our flagship electromagnetic and semiconductor solvers, will provide a comprehensive solution for on-chip, 3D integrated circuit and chip-package-system electromagnetics and noise analysis.

Conference Call Information

ANSYS will hold a conference call at  8:30 a.m. Eastern Time  on February 28, 2019 to discuss fourth quarter and fiscal year 2018 results. The Company will provide its prepared remarks on the Company’s investor relations homepage and as an exhibit in its Form 8-K in advance of the call to provide shareholders and analysts with additional time and detail for analyzing its results in preparation for the conference call. The prepared remarks will not be read on the call, and only brief remarks will be made prior to the Q&A session. The Company also posted a complementary investor presentation titled "4Q 2018 Investor Presentation" that can be accessed by clicking News & Events, then Presentations on our website at https://investors.ansys.com .