An analysis of the job to be done (i.e. an analytical study of the tasks to be performed to determine their essential factors) written into a job description so that the selectors know what physical and mental characteristics applicants must possess, what qualities and attitudes are desirable and what characteristics are a decided disadvantage;
In the case of replacement staff a critical questioning of the need to recruit at all (replacement should rarely be an automatic process).
Effectively, selection is 'buying' an employee (the price being the wage or salary multiplied by probable years of service) hence bad buys can be very expensive. For that reason some firms (and some firms for particular jobs) use external expert consultants for recruitment and selection.
Equally some small organizations exist to 'head hunt', i.e. to attract staff with high reputations from existing employers to the recruiting employer. However, the 'cost' of poor selection is such that, even for the mundane day-to-day jobs, those who recruit and select should be well trained to judge the suitability of applicants.