First, we can introduce more precision into the development process to prevent many of the errors. Second, we can introduce, at the end of each process, a separate verification step to locate as many errors as possible before proceeding to the next process. This approach is illustrated in Figure 6.2. For instance, the external specification is verified by comparing it to the output of the prior stage (the statement of objectives) and feeding back any discovered mistakes to the external specification process. (Use the code inspection and walkthrough methods discussed in Chapter 3 in the verification step at the end of the seventh process.)we can introduce more precision into the development process to prevent many of the errors.