Slide 39 of 99
According to the May'86 Space Station assembly sequence, the first element would be launched in January 1993. The Station would support man-tended operations after the sixth Shuttle assembly mission in August 1993 and be ready for permanent occupation after the ninth mission in January 1994. Initial Operating Capability (IOC) would be achieved after 21 flights -- twice as many as the 1984 estimate.
The “Dual Keel” Space Station's final flight sequence overview in October 1986 had to insert an additional eight Shuttle flights into the manifest. By this time, increased complexity and Shuttle payload capability reductions had increased the required number of assembly flights to more than 30 for an Initial Operating Capability (IOC) vs. 8-10 in 1984.