definiens: ] ( as defined below in this Section 11 ) and BUYER requests support from SELLER to investigate such [ False Positive Occurrence ], SELLER shall employ reasonable efforts to develop and implement an agreed upon action plan to identifY the cause of[the occurrence ] . Once the cause of[the occurrence ] has been deternlined, BUYER and SELLER will cooperate to make a scientific assessment of the best approach to correct the cause of [ the occurrence ] . Considerations in that assessment will include such variables [ as whether the occurrence is peculiar to a particular USPS sorting site, whether the occurrence arose from a source external to the products provided hereunder for use in BUYER 's biohazard agent detection system, where intervention can be made, and the likelihood of success of trying to correct the cause of the occurrence by means of changes to the products supplied by SELLER or by changes to products supplied by others or by changes to be made by BUYER, or by changes to be made by the USPS ] . Tfthe parties agree in their reasonable scientific judgment that [ changes should be made to SELLER 's products and that SELLER 's proposed changes would have a high probability of success ], SELLER will use reasonabl e efforts to develop an agreed upon action plan and SELLER will use commercially reasonable efforts to implement said action plan to correct the cause of [ the occurrence ] . In developing and implementing the action plan to identify the cause of [ the occurrence ], assessing the solutions, and in developing and implementing the action plan to correct the cause of [ the occurrence ], SELLER agrees to spend up to a limit of$[500,000 [, at its then standard hourly time and material rates, to modify its products and/or processes, the goal of that modification being to prevent [ any reoccurrence of the event ] . Once the spending limit has been reached by SELLER, any additional effort may be contracted for by way of a change order or a separate purchase order, either to be negotiated between the parties at the time . For purposes of this Purchase Order, a [ means one or more positive BDS results ( i.e., 4 - plex cartridge results for both pxOI and px02 are positive ) indicating the presence of bacillus anthracis in the sample, and the Laboratory Response Network ( LRN ) culture shows no growth of bacillus anthracis, indicting that bacillus anthracis was not present in the sample . However, if USAMRllD or LRN testing indicates that DNA that matches USAMRllD 's sequences for pxOI and px02 is present, it will not be deemed a false positive event ]