Past patterns can be an interesting contrast. During WWII generals were hired and fired quickly. Because the practice was pervasive there was no big stigma to being fired and there were always alternative positions to try. It also helped that there was a general structure which was not explicit or required but was broadly exhibited. That is, new hires were expected to show basic proficiency within two weeks and to make a significant contribution with in six weeks. Since a relatively quick test of skills was built in to the management structure there was less pressure on initial evaluation.