Mesenchymal stem/stromal cells (MSCs) are multipotent stem cells that can be isolated from bone marrow, adipose tissue, the umbilical cord, dental pulp, etc. These cells have unique properties that give them excellent therapeutic potential, including immunoregulation, immunomodulation, and tissue regeneration functions. MSC-based products are considered advanced therapy medicinal products (ATMPs) under European regulations (1394/2007); thus, they must be manufactured under good manufacturing practices and via effective manufacturing methods. The former can be achieved via a proper laboratory design and compliance with manufacturing protocols, whereas the latter requires an approach that ensures that the quality of the products is consistent regardless of the manufacturing procedure. To meet these daunting requirements, this study proposes an exchangeable approach that combines optimized and equivalent manufacturing processes under the Quality by Design (QbD) principle, allowing investigators to convert from small laboratory-scale to large-scale manufacturing of MSC-based products for clinical applications without altering the quality and quantity of the cell-based products.