A large manufacturing company decides to implement self$-$managed teams in which team members are given the latitude to jointly decide how their work is to be done. Until now, the company deployed closely managed teams in which team members have little discretion over tasks and are told not only what to do but how to do it$.$ A pilot that was conducted in three of the company's production facilities found an $18$ percent increase in labor productivity after the introduction of self$-$managed teams. However, six months after the self$-$managed teams were implemented, it turned out that in $12$ of the company's $89$ production facilities, the productivity didn't change, whereas in the other $67$ facilities, productivity increased between $10$ and $20$ percent.

What could be the reason that the productivity in $12$ of the company$$s $89$ production facilities did not change?

The managers at the $12$ facilities may have lacked the necessary skills to implement the self$-$managed teams.

This could just be coincidence.

Self$-$managed teams may have little or no impact on labor productivity.

All of the three.