Dear Qasim,
What you have written is about recruitment. Yes, selecting the "right" candidate for the job was a challenge, it is today, and will remain so in the future too.
Nevertheless, your challenge is if the candidate you select for a job quits the company. In that case, you need to understand the culture of the company. If the freshly hired employees do not wish to continue with the company, then it could be because of the mismatch between the candidate's expectations and the company's culture. The second reason could be poor leadership of the HODs. While HR may hire the best of the best people, what if the HOD fails to motivate him/her or maltreats him/her? Under such circumstances, the employees will quit anyway.
One of the solutions to your challenge is to do an attrition analysis and find out of the total candidates hired, what % of the employees quit on their own. Was their exit regrettable or non-regrettable?
Your second challenge is you are required to terminate the freshly hired employees during their probation itself. This is clearly a recruitment failure. In such cases, you need to study why your recruitment went wrong. What questions did you ask during the interview and what was the behavior at the workplace? Why did the recruitment team fail to gauge the behavior or performance of the candidate is a matter of study.
The solution to your second challenge is to strengthen the recruitment process. Include more technical and non-technical tests. Secondly, are the interviewers formally trained to conduct the job interviews? Who has certified them to become interviewers? Is it that interviewers are not formally trained but by the virtue of the length of their service, it is assumed that they are fit to conduct the interviews? Do you conduct competency-based interviews?
Your problem is much deeper. While you employ solutions based on the replies by the seniors of this forum, much depends on whether the implementation was effective or not.
Thanks,
Dinesh Divekar