Revenue from Contracts with Customers

Oncology Services Revenue

The Company adopted ASC 606, Revenue Recognition - Revenue from Customers ("ASC 606") on May 1, 2018 using the modified retrospective method for all contracts not completed as of the date of adoption. The reported results for both the three months ended January 31, 2020 and 2019 reflect the application of ASC 606. In accordance with ASC 606, revenue is now recognized when, or as, a customer obtains control of promised services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these services.

A performance obligation is a promise (or a combination of promises) in a contract to transfer distinct goods or services to a customer and is the unit of accounting under ASC 606 for the purposes of revenue recognition. A contract's transaction price is allocated to each separate performance obligation based upon the standalone selling price and is recognized as revenue, when, or as, the performance obligation is satisfied. The majority of the Company's contracts have a single performance obligation because the promise to transfer individual services is not separately identifiable from other promises in the contracts, and therefore, is not distinct.

The majority of the Company's revenue arrangements are service contracts that are complete within a year or less. There are a few contracts that range in duration between 1 and 3 years. Substantially all of the Company's performance obligations, and associated revenue, are transferred to the customer over time. Most of the Company's contracts can be terminated by the customer without cause. In the event of termination, the Company's contracts provide that the customer pay the Company for services rendered through the termination date. The Company generally receives compensation based on a predetermined invoicing schedule relating to specific milestones for that contract. In addition, in certain instances a customer contract may include forms of variable consideration such as performance increases or other provisions that can increase or decrease the transaction price. This variable consideration is generally awarded upon achievement of certain performance metrics. For the purposes of revenue recognition, variable consideration is assessed on a contract-by-contract basis and the amount to be recorded is estimated based on the assessment of the Company's anticipated performance and consideration of all information that is reasonably available. Variable consideration is recognized as revenue if and when it is deemed probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved in the future.

Amendments to contracts are common. The Company evaluates each amendment which meets the criteria of a contract modification under ASC 606. Each modification is further evaluated to determine whether the contract modification should be accounted for as a separate contract or as a continuation of the original agreement. The Company accounts for amendments as a separate contract if they meet the criteria under ASC 606-10-25-12.

Other TOS revenue represents services provided to the pharmaceutical and biotechnology companies. The Company does not consider these services part of their core product offerings.

The following tables represents disaggregated revenue for the three and nine months ended January 31, 2020 and 2019:



	Three Months Ended January 31,				Nine Months Ended January 31,
	2020		2019		2020		2019
Pharmacology services	$	8,843	$	5,988	$	22,732	$	18,037
Personalized oncology services	169		416		581		1,024
Other	—		26		62		287
Total oncology services revenue	$	9,012	$	6,430	$	23,375	$	19,348

Contract Balances

Contract assets include unbilled amounts typically resulting from revenue recognized in excess of the amounts billed to the customer for which the right to payment is subject to factors other than the passage of time. These amounts may not exceed their net realizable value. Contract assets are classified as current. Contract liabilities consist of customer payments received in advance of performance and billings in excess of revenue recognized, net of revenue recognized from the balance at the beginning of the period. Contract assets and liabilities are presented on the balance sheet on a net contract-by-contract basis at the end of each reporting period. There were no material contract assets or liabilities recorded on the condensed consolidated balance sheets as of January 31, 2020 and April 30, 2019.