You are the project manager for constructing a custom house. On one of your Monday morning inspections of the progress, you notice a spot of flaking paint on the outside of the house. The outside was painted on Friday. On closer inspection, you see that the entire north side of the house has issues with the paint peeling and flaking. The other sides of the house appear fine. Select one or more of the 7QC tools to investigate this problem. What else would you do?