I agree completely with Diane... I think teaching dogs to eliminate in their crate is an AWFUL idea. the companies that are selling those systems should be ham strung, IMO.
I also think that a crate is too small an area for your puppy to be spending long periods of time in, except over night. During the day, I think it's much kinder (and better for potty training) to set a puppy or young dog up in an ex-pen with a crate, left open, as a bed in one end (or a comfy donut bed if they prefer that)) and their potty on the other end. This gives them room to move around and play a little while avoiding their potty.
Dogs that have been raised with clean potties do NOT like to pee or poop on soiled potties... you will probably have to make sure it is cleaned up at least daily. I don't like pee pads because so many dogs, Havanese in particular, destroy or even eat them. At best gross, at worst, dangerous. I MUCH prefer an enclosed system, like the UgoDog. Lots of people use pee pads in the UgoDog (as it is designed). I prefer to use pine pelleted horse bedding or wood stove pellets under the grate. They are completely biodegradable, so better for the environment than plastic backed pee pads, and also absorb any odor MUCH better.
As far as the bells are concerned, some dogs catch on to the idea right away, some need a LOT of teaching and reinforcement, and others, like my Kodi find them aversive for some reason. He is a VERY smart, VERY trainable dog. (look at all the titles on his registered name!
) But he REFUSED to touch the bells independently... EVER. I finally took them down because all they ere doing was scratching my wood work. I know they work great for some people. (usually AFTER the dog REALLY understands going outdoors to potty, but before they have developed their own signal) Kodi eventually learned to use his own voice to tell us when he needed to go out, Pixel scratches on the glass of the back door. Panda hasn't developed a signal yet, but she usually goes out when the other two do, so it is rarely an issue. I've considered putting the bells up for her, but I'd prefer for her to develop her own "portable" signal, since we travel with them so much.
Finally, when you are talking about a "longer work day", how long and how often? If it is up to 6 hours, and not very frequently, I think she'd be fine in an ex-pen set up as Diane and I have described. If it's longer than that, or if it's a regular thing, (say, a couple of days a week) it would really be much better for her if you could set up someone to come in and take her for a short walk and play with her a bit in the middle of the day. Havanese were purpose-bred as a companion breed, and long periods without human company are hard on them.