Achieving the price stability target of 2 percent means attaining a situation in which the observed CPI is 2 percent on average over the business cycle. Thus, it naturally is assumed from the outset that there will be phases when the observed CPI overshoots 2 percent.
However, given that there is a time lag before monetary policy takes effect, it is an exceptional and very strong commitment by a central bank to continue with monetary easing until the observed inflation rate exceeds 2 percent and stays above that level in a  7  stable manner.