Based on studies done by Mentzer et al.
(2001), Sohal et al. (2002) and Kotzab et al.
(2005), this study categorizes integration level of
TSC business processes into four namely Level
1, Level 2, Level 3 and Level 4. In Level 1,
integration of TSC business processes occurs
within the company; in Level 2, integration of
business processes takes place between the
company and its suppliers; in Level 3; integration
of business processes happens between
company and its customers; in Level 4; integration
of business processes emerges among
suppliers, company and customers.