hit–and–miss 
/ˌhɪtn̩ˈmɪs/ adjective
/ˌhɪtn̩ˈmɪs/ adjective : sometimes successful and sometimes not : not always good or successful
▪ The company has relied on a hit-and-miss [=hit-or-miss] approach to developing new products.
▪ The company has relied on a hit-and-miss [=hit-or-miss] approach to developing new products.
