Dear Tamanna,
If speeches were to improve the employee productivity then management science in general and HR management in particular would not have taken birth at all.
Employee productivity is too complex. It depends on
motivation of workers,
culture of interdependence and cooperation, quality raw materials, quality of the machines that they use, leadership qualities of the managers, their own job knowledge, remuneration as per market standards and so on.
Next thing for you is to do the time and motion studies. Also study why and how much scrap is generated. Study the cycle time for each process. Study the layout of the factory as well.
Ok...
Dinesh V Divekar