What challenges face HR managers with regard to workforce availability and quality?

Workers tend to differ in their schedule availability and their work quality. It is the HR managers' responsibility to address those different preferences to maximize efficiency and productivity.

For example, workers may not be available because of religious holidays, or illness, or family obligations. Then travel, work assignment and other things have to reassessed.

Also, workers have different abilities. Some produce better work than others. Then HR has to determine how to properly allocate these individuals. Or, they may have to decide whether they need to hire or fire to maintain or improve the company's productivity.