This work investigates the pervasive issue of project change in real-world practice. The focus is on the perception of the importance of such change and the data used to make decisions. This is a multiple case study to find indications of trends. The interviewees were selected for their wide range of viewpoints, from project manager to program manager and from group leader to president. Organizations included transportation, marketing, medical products, high technology, and two public works representing municipal governments rather than private industry. Overwhelmingly, change was perceived as important or vital for product success, and data used to evaluate project change was perceived as important. Cost was by far the most common data factor. The iron triangle of cost, quality, and time were the main factors examined. Expert judgment was the most important aspect of estimating the value of data. Decision processes and responsibilities varied with organization type and size. A major finding is that few data items were used to evaluate whether or not to go ahead with project change. It was most common to use just one item. This may be a good choice of focus on the part of the organization. Or, it could be a missed opportunity to make a better decision.