Business leaders have long recognized systemic thinking as a useful source of ways to improve products, services, and processes. Examples of approaches based on systemic thinking include value analysis and process reengineering, which have proven effective in making the various elements of a product or service fit together and in integrating partial business functions (such as order processing, inventory management, purchasing, and production planning) into comprehensive business processes. Supply chain management and organisational learning, among other disciplines, have derived from this effort.