What are the advantages and disadvantages of overtime?

You use overtime when you need the work to be done on time as you don't have enough time. But there should  a trust between the employee and the employer as in fact the situation really need overtime. 

So the manager should decide that 

IF it limited then it can help to increase per day production. but its too long on every day then it may reduce workers concentration on Job due to it may lead to occur accident and production loss. 

The potential advantages of using overtime working include:

• a more flexible workforce
• the ability to deal with bottlenecks, busy periods, cover of absences and staff shortages without the need to recruit extra staff
• increased earning for employees
• avoidance of disruption to jobs where the workload is more difficult to share, eg transport and driving
• the ability to carry out repair and maintenance which has to be done outside normal working hours

However, disadvantages may include:

• the expense of premium overtime rates
• inefficiency if employees slacken their pace of work in order to qualify for overtime
• regular long working hours, which can adversely affect employees' work, health and home lives - read how to promote good work/life balance within your business
• fatigue, which may increase absence levels and lead to unsafe working practices
• employee expectations of overtime, leading to resentment and inflexibility if you try to withdraw it

Agree 100% with Mr. Mohammed Bin Salmah answer

Besides less salary of no overtime,you have less knowledge of what your profession.more overtime more knowledge of your carrier,and besides that more earn.