When looking at efficiency from a purchasing perspective, resources would be
related to the purchasing function. Van Weele (2005, p. 255) considered purchasing
efficiency as a “relationship between planned and actual sacrifices in order to realize a
goal” and contends that the essential resource is cost. Similarly, Janda and Seshadri
(2001) argued that purchasing efficiency is the ratio between purchasing inputs and
purchasing outputs and pointed out that efficiency reduces costs and order processing
times. They also claimed that the main strategy for making purchasing more efficient
should be cooperative negotiations and interactions with a limited number of suppliers.
This implies integrating suppliers into the value chain and striving for a win-win
situation rather than maximizing self-gain.