Dear Expert, could you please answer this questions? Thanks heap!!

Explain the three levels of supplier activities and costs that are incurred by an organisation?

Explain how 'collaborative relationships' with suppliers are essential when the strategic focus of a firm is cost leadership?

Explain why calculating customer profitability assists in the management of customer-driven costs?

Define the term 'bottleneck' and describe how the application of the 'theory of constraints' can assist management in production?