Which variance is directly impacted if the employees who build the product go on strike and temporary workers who are slower and not as skilled areâ hired?

Labor efficiency variance is directly impacted if the employees who build the product go on strike and temporary workers who are slower and not as skilled are hired. Variance is the difference between actual result and your expected or desired result. 
When we calculate the comparison of actual hours worked with the standard hours allowed is labor efficiency variance. The comparison is calculated at the standard labor rate.

The business cycle is the periodic but irregular up-and-down movement in economic activity, measured by fluctuations in real gross domestic product (gdp) and other macroeconomic variables. a business cycle is typically characterized by four phases—recession, recovery, growth, and decline—that repeat themselves over time. economists note, however, that complete business cycles vary in length. the duration of business cycles can be anywhere from about two to twelve years, with most cycles averaging six years in length. some business analysts use the business cycle model and terminology to study and explain fluctuations in business inventory and other individual elements of corporate operations. but the term "business cycle" is still primarily associated with larger (industry-wide, regional, national, or even international) business trends.