Control charts are useful in stabilizing a process because they help identify any "special causes" that may be acting on a process. Before a process can be improved, the process must be stable (special cause variation must be eliminated; only common cause variation should be left in the process).
Describe some process with which you are familiar (e.g., a process in your place of employment) and discuss how one of the attributes control charts (p, np, c or u) could be used to stabilize the process. What type of data would need to be collected? Are there potential challenges in obtaining such data? What might be some plausible sources of special cause variation in the process?