Some job design is from the 1950's and companies have not updated them to reflect today's combination and availability of specific skills and abilities. Job Design needs to be flexible and fluid based on skill availability, based on the local labor market. Consider taking the job requirements for 3-4 jobs and creating 2-5 rescoped positions that include more attainable combinations of skills and experience to allow the position to be filled faster. Also think of breaking apart jobs that specific people have in the organization with critical skills to minimize the negative impact if the person were to unexpectedly leave. We have redesigned and modernized the phone since the 1950s, why wouldn't job design by any different.