How important is it to train/coach new and old employees?

Training and Coaching can help employess to learn something new ,and also this can avoid wastage of resource . 

There are constant tech advances in the world. To remain in the ball game, training is always required no matter the experience of a senior or a freshy. A weak link could crumble down an entire infrastructure. As the Romans used to say "when in Rome, live like Romans". You always need to make sure your competition doesn't get the better of you.

1. Training increases efficiency / productivity,

2. Reduces cost & wastage 

3. Keeps employee morale high by building confidence on new technologies with up to date knowledge. 

4. Promotes creativity

for the new ones its necessary, for the old ones its a boost, refresh ........ i believe its really important

for new employees you should provide a mediocre training and let them ask you when needed because they think they got it under control , and old employees should have extensive training based on the performance analysis .  

New or old employees not matter ,matter is reach on time on job or any  slected place which is internally related with timmings..Rules obey is equal for new or old .