Below is a list of various repairs and improvements that pianos can require:
Regulation a piano is just adjusting all of the mechanical parts so that the piano works as it was designed to work from the factory. These adjustments are necessary to compensate for the effects of wear and humidity over time. These adjustments help the touch of the piano feel right. It will be more even, responsive, and uniform allowing for better control of the dynamic range of the piano.
When the technician is tuning a piano he (or she) may make recommendations on regulation adjustments that can help the piano play better.