Revenue Recognition. We enter into agreements to sell products (hardware and/or software), services and other arrangements (multiple element arrangements) that include combinations of products and services. We recognize revenue, net of trade discounts and allowances, provided that (1) persuasive evidence of an arrangement exists, (2) delivery has occurred, (3) the price is fixed or determinable and (4) collectability is reasonably assured. Delivery is considered to have occurred when title and risk of loss have transferred to the customer for products, or when the service has been provided. We consider the price to be fixed or determinable when the price is not subject to refund or adjustments. At the time of the transaction, we evaluate the creditworthiness of our customers to determine the appropriate timing of revenue recognition. Provisions for discounts, warranties, returns, extended payment terms, and other adjustments are provided for in the period the related sales are recorded. Product Revenue. Product revenue includes revenue generated from the sales of our analytical instrumentation, software and consumables. Our product revenue is generated predominantly from the sales of various types of analytical instrumentation. Product revenue, including sales to resellers and distributors, is reduced for estimated returns when appropriate. For sales or arrangements that include customer-specified acceptance criteria, including those where acceptance is required upon achievement of performance milestones, revenue is recognized after the acceptance criteria have been met. For products that include installation, if the installation meets the criteria to be considered a separate element, product revenue is recognized upon delivery, and recognition of installation revenue is delayed until the installation is complete. Otherwise, neither the product nor the installation revenue is recognized until the installation is complete. Where software is licensed separately, revenue is recognized when the software is delivered and has been transferred to the customer or, in the case of electronic delivery of software, when the customer is given access to the licensed software programs. We also evaluate whether collection of the receivable is probable, the fee is fixed or determinable and whether any other undelivered elements of the arrangement exist on which a portion of the total fee would be allocated based on vendor-specific objective evidence. Service Revenue. Revenue from services includes extended warranty, customer and software support including, Software as a Service (SaaS), consulting including companion diagnostics and training and education. Service revenue is deferred and recognized over the contractual period or as services are rendered and accepted by the customer. For example, customer support contracts are recognized ratably over the contractual period, while training revenue is recognized as the training is provided to the customer. In addition, the four revenue recognition criteria described above must be met before service revenue is recognized. Revenue Recognition for Arrangements with Multiple Deliverables. Our multiple-element arrangements are generally comprised of a combination of measurement instruments, installation or other start-up services, and/or software and/or support or services. Hardware and software elements are typically delivered at the same time and revenue is recognized upon delivery once title and risk of loss pass to the customer. Delivery of installation, start-up services and other services varies based on the complexity of the equipment, staffing levels in a geographic location and customer preferences, and can range from a few days to a few months. Service revenue is deferred and recognized over the contractual period or as services are rendered and accepted by the customer. Revenue from the sale of software products that are not required to deliver the tangible product's essential functionality are accounted for under software revenue recognition rules which require vendor specific objective evidence (VSOE) of fair value to allocate revenue in a multiple element arrangement. Our arrangements generally do not include any provisions for cancellation, termination, or refunds that would significantly impact recognized revenue. We have evaluated the deliverables in our multiple-element arrangements and concluded that they are separate units of accounting if the delivered item or items have value to the customer on a standalone basis and for an arrangement that includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is considered probable and substantially in our control. We allocate revenue to each element in our multiple-element arrangements based upon their relative selling prices. We determine the selling price for each deliverable based on a selling price hierarchy. The selling price for a deliverable is based on VSOE if available, third-party evidence (TPE) if VSOE is not available, or estimated selling price (ESP) if neither VSOE nor TPE is available. Revenue allocated to each element is then recognized when the basic revenue recognition criteria for that element have been met. We use VSOE of selling price in the selling price allocation in all instances where it exists. VSOE of selling price for products and services is determined when a substantial majority of the selling prices fall within a reasonable range when sold separately. TPE of selling price can be established by evaluating largely interchangeable competitor products or services in standalone sales to similarly situated customers. As our products contain a significant element of proprietary technology and the solution offered differs substantially from that of competitors, it is difficult to obtain the reliable standalone competitive pricing necessary to establish TPE. ESP represents the best estimate of the price at which we would transact a sale if the product or service were sold on a standalone basis. We determine ESP for a product or service by using historical selling prices which reflect multiple factors including, but not limited to customer type, geography, market conditions, competitive landscape, gross margin objectives and pricing practices. The determination of ESP is made through consultation with and approval by management. We may modify or develop new pricing practices and strategies in the future. As these pricing strategies evolve changes may occur in ESP. The aforementioned factors may result in a different allocation of revenue to the deliverables in multiple element arrangements, which may change the pattern and timing of revenue recognition for these elements but will not change the total revenue recognized for the arrangement. For sales arrangements that include equipment lease along with other products or services, revenue is allocated to the different elements based on the Revenue Recognition for Multiple Element Arrangements. Each of these contracts is evaluated as a lease arrangement, either as an operating lease or a capital (sales-type) lease using lease classification guidance. Deferred Revenue. Deferred revenue represents the amount that is allocated to undelivered elements in multiple element arrangements. We limit the revenue recognized to the amount that is not contingent on the future delivery of products or services or meeting other specified performance conditions.