Text should refer to following articles.

Article 1:
Richard Normann, and Rafael Ramirez,. “From Value Chain to Value Constellation: Designing Interactive Strategy” Harvard Business Review, Volume 71, Number 4 (July-August 1993), pp. 65-77.

Article 2:
Eric Harmon, Scott C. Hensel, and Timothy E. Lukes, “Measuring performance in services”, McKinsey Quarterly, 2006 Number 1.

Writing should also be guided with following sentences:
Service businesses may not directly follow the economies of scale common in industrial businesses. Modularity and interdependence in cooperative arrangements may provide better service to end customers, as well as higher profitability to services organizations. Service providers may establish relationships with peers, with upstream and/or downstream partners, with universities, and/or with governmental agencies. These may enable greater immediate or future competitiveness for an independent service business, or an ecosystem of complementary service providers.