SFMTA noted that of 37 schedule updates submitted by Tutor Perini between December 2014 and December 2017, 21 were rejected "due to multiple and repetitive issues that vary from incorrect working sequences to unrealistic forecasted completion dates to artificially steering the schedule longest path through certain portions of the project". Contrary to TPC's claims, SFMTA stated that ground conditions were as expected from preliminary surveys, but TPC's "mining productivity has not been as planned" and directed TPC to develop a recovery schedule. In January 2018, for example, TPC modified their construction sequence at Chinatown station and were able to shave 18 days off the schedule, changing the estimated revenue service date to November 22, 2019. By May 2019, the estimated opening had slipped to February 2020. In September 2019, it was announced that the opening was delayed yet again, this time to mid-2021. Another delay to late 2021 was announced in June 2020, followed by a further delay to 2022. Major construction is expected to be completed in March 2021, with final completion by that September.