What is the best strategy to purchase a material in large quantities and that requires a very short delivery time?

In the short term, for strategic items where the supplier’s strength outweighs the company’s and the indicated strategy is diversification, the company should consolidate its supply position by concentrating fragmented purchased volumes in a single supplier, accept high prices, and cover the full volume requirements through supply contracts. To reduce the long-term risk of dependence on a single source, however, the company should also search for alternative suppliers or materials or even consider backward integration to permit in-house production. On the other hand, if the company is stronger than the suppliers, it can spread volume over several suppliers, exploit price advantages, increase spot purchases, and reduce inventory levels.