If you are too busy then the best way of house training your puppy is to place him/her in a crate in an area nearby where you are working. You might think this is a cruel thing to do but look at it this way – if you allow your puppy to roam around every room in the house and you are too busy to keep an eye on him/her then what will happen? Your puppy will think this is his area plus he/she will go to the toilet wherever he/she pleases and will also decide what he/she wants to chew on – see how to stop my dog from chewing everything. As you are too busy to pay attention you then find out later that the puppy has toileted inside. You scold him/her and take him/her outside. At this point the puppy has no idea what he/she has done because he/she toileted an hour ago and you didn’t catch him/her in the act. So then this becomes the behaviour because the puppy doesn’t know any different. You decide that it is too difficult to house train your puppy and he/she is seconded to the outside yard only. You are then too busy to play with him/her, so he/she starts barking, there are chew toys but the reticulation is a better toy to play with. You get cross and start punishing him/her. The puppy then starts to dig in the garden, etcetera, etcetera – do you see the pattern of behaviour? By commencing your house training in a crate (and this is only while the puppy is learning) for a short period of time with the chew toys (and treats) and some soft bedding and by taking him/her outside for toilet every half hour or so you are instigating a correct behaviour pattern which will set up the puppy for being a valuable member of the family and understanding the rules.
If you need to go out and leave your puppy inside the home then the house training exercise should be confining him to an enclosed area or laundry, bathroom or suchlike. Make sure it is equipped with a bed or soft mat for him to sleep, a container of fresh water, some chew toys with treats in them and make a toilet out of a box with some soil or turf in it. This will need to be placed as far from the bedding as possible. Otherwise, fence off an area in the yard so the puppy has an area to play in while you are out. Make sure you leave water and toys for him/her in this area.
You will find that house training your puppy will be successful through repetition and consistency with praise, rewards and treats.