I once had all the ministry leads at my church sit with me and explain to me what they were doing in their various ministries (I was an Elder in the church, you see). After they had all offered a summary of their ministries, I asked them how they determined if they were succeeding in what they were doing. They were all surprised by my question and had little to offer in response. I was surprised myself at their surprise and asked them why they had been operating without any means of evaluating if they were doing well in their respective ministries. It's just how things had always been done, they told me.
That there was a ministry seemed to be the important thing, not that it was necessarily achieving a godly end. Because this was so, there were a number of ministry leads whose walk with God was not good. All that had been required for their leading a particular ministry was their willingness to do so and no obvious, gross sin disqualifying them. As you can imagine, the ministries were rife with small, subtle seeds of false and carnal teaching, and had drifted into being a lot of "sound and fury signifying nothing" spiritually.
I wouldn't, then, be keen to have a bunch of approved Bible studies that just anyone in the church can take out and use in a sort of ad hoc study they lead on their own. Too often, at least in my experience, this is the "blind leading the blind," involving a lot of erroneous "this is what I think" discussion and the elevation of personal feeling and experience above the declaration of God's word.