We should be very careful not to follow rules and regulations simply for their own sake, forgetting the purpose behind them. For example, we may chant a particular number of rounds per day thinking that we are "safe" because we are meeting out quota; but if we do not have a sense of what chanting the holy name is meant to be about, we may think that it doesn't matter what else we do while we chant, and thus commit namaparadha. It is all right to feel commitment to our sadhana activities, but don't perform them mechanically. Mechanical sadhana-bhakti does not produce bhava (pure spiritual emotion).
Lectures from a Disciple, Vol. 2, Purpose of Sadhana-bhakti