There are too many people who connect Twitter and Facebook together so all of their tweets are automatically posted on their Facebook accounts. Some people who connect their Twitter and Facebook accounts do so just to make sure something appears on their Facebook account every day while others think they are effectively systematizing their Facebook accounts.
However, if your Facebook and Twitter accounts are connected, all of your tweets will get posted on your Facebook account. If you are having a conversation with one of your friends or business partners on Twitter, all of the tweets you send during that conversation will also get posted to your Facebook account. The two problems that occur is that some people will not care for the conversation, but the bigger problem is that the people viewing your posts only get to see your part of the conversation. They do not get to see how your friend or business partner is responding to your tweets.
While it is possible to schedule posts, it is not possible to run a successful, systematized social network. It is possible to run a successful social network, but attempting to systematize that social network results in you sacrificing the most important thing about social media: being social. Instead of trying to systematize Facebook by posting your tweets to Facebook, you should create quality posts on Facebook (scheduled or at the moment) and respond to the people who respond to your Facebook posts.
Social media was created to dramatically increase the ability for people to communicate with others in the same town, city, state, country, continent, and world. In order to be successful on social media, we need to use social media for the reason it was created in the first place. Connecting Facebook and Twitter in an attempt to systematize your Facebook account is not the right way to get the job done.