Boeing said Monday it has begun building the first single-aisle 737 at the program's new production rate of 35 airplanes a month, up from the previous 31.5 airplanes a month.

Boeing said Monday it has begun building the first single-aisle 737 at the program’s new production rate of 35 airplanes a month, up from the previous 31.5 airplanes a month.

The Renton plant is pushing for efficiency by making its assembly processes leaner, moving some production areas, and decommissioning outdated equipment while making capital investments in new equipment to increase capacity.

The new production rate began with the loading of metal parts into a new wing spar assembly tool, which drills about 1,700 holes and inserts fasteners to make the spar. It is the ninth such machine at the Renton factory.

To meet burgeoning worldwide market demand for single-aisle jets, the 737 production rate will increase to 38 airplanes a month in the spring of 2013 and to 42 airplanes a month by the summer of 2014.