Why we send 2-3 engineers for installation, commissioning and training for cashe

Usually we will send 2-3 engineers for installation, commissoning and training. some customers will ask: why you need so many 
engineers?  let me explain you here: 
1-2 engineers will install and commissioning the whole line, this process need 10-15 days, then 
they can go back, for the last engineer, he have experienced in cashew nut processing factory for more than 10 years, he will do 
training work. his training includes whole factory management, detailed operation, staff assignments, machine maintenance, 
and experience to get highest whole kernel rate and peeling rate.  with his help, customers can use least staff, least energy,least waste 
rate to get highest whole kernel rate and peeling rate. in this case, the customers will get rid of many mistakes. According to customers'
request, this engineer usually stays for 1-3 months.