The company's core personnel: (is the person who has the power to respond to the claim of the company Siemens, and is the main contact between companies/contractors who deliver the raw materials to the company Siemens)
Personnel of the Company: (a person who has the authority to respond to the demands of Siemens and is the main contact between a contractor / supplier of raw materials, Siemens).
The company's main: personnel. (is a competent person in response to the demands of the Siemens and contact between the main contractor / supplier of raw materials to the Siemens)