The document discusses the role of the Theory of Constraints (TOC) in the success of IT systems, specifically Enterprise Resource Planning (ERP) systems. It first provides background on ERP systems and their benefits and challenges in integrating business functions. It then discusses some limitations of ERP, including high costs, need for business process reengineering, and inability to adapt to changes. The document introduces TOC and its five focusing steps to identify and address constraints. It argues that combining ERP with TOC can help address ERP shortcomings by focusing on constraints throughout the project lifecycle. Case studies show improvements like reduced planning times and inventory when TOC was applied. The conclusion is that TOC can help ERP systems