Excellent reliability from Suncor's oil sands operations was one of the factors driving Suncor's extremely low cash operating cost per barrel. Overall, Suncor's upstream production was 602,000 boe/d, which represented a 10% increase from Q1 2015. This increase was largely driven by record oil sands production of 440,000 boe/d, which represented a 13% increase from Q1 2015, and included record production of synthetic crude (which is the product produced by Suncor's upgrading facilities that uses oil sands bitumen as an input). These huge improvements in production are due to the fact that Suncor had improved reliability across its oil sands assets, had low amounts of maintenance, and had no unplanned downtime. This should improve going forward, as a major source of Suncor's previous outages and downtime occurred in the Syncrude oil sands mining project.