Two longtime Parker Hannifin Corp. (NYSE: PH) executives who lead key operating units at the Mayfield Heights-based maker of motion and control technologies are retiring at the end of the year. The transition will be smooth, as their successors will start on Jan. 1, 2024. Parker on Monday, Oct. 30, announced that William R. "Skip" Bowman, vice president and president of the Fluid Connectors Group, and Roger S. Sherrard, VP and president of the Aerospace Group, will retire on Dec. 31 after 40 and 34 years, respectively, of work at the company.