Definitions

1. Value chain
   "The chain of activities - and linkages between them -  performed by a firm, which are the source of competitive advantages" -Johnson and Scholes (1999), Exploring Corporate Strategy

2. Value system
   "The set of value chains that come together including suppliers, manufacturers, processors, distributors, traders and retailers" -Michael Porter (2009)* 

3. Supply chain
   The network of interconnected firms through which materials, products, information, and money flow from suppliers to the end customer. It is different way of looking at value systems. 

4. ??? system
   The network in which firms, support organizations and government come together to create competitive advantages in international trade.

*  Exchange of thoughts with authors.