Critically analyse the value-chain model of Michael Porter (1985).

Discuss the model’s suitability, potential and whether its limitations have been addressed in any new framework. The discussion should be in the context of firm’s competitiveness. Use various companies that operate in different fields as examples , carefully analyse, compare and contrast if the model was effective or not and how it was used for each company.  8 to 10 academic sources from journals preferably. 

I chose question 1.