The system has been built to receive SMS messages from Twilio and respond with booking appointments using Azure Bot Service, Language Understanding, and LUIS. The system uses a waterfall dialog flow to manage the conversation between the user and the bot. The LUIS model is used to analyze the incoming message and determine the intent of the user's query. The system also includes features such as validation of doctor names and appointment dates, and the ability to send confirmation messages to users. The system can be deployed to Azure App Service and tested using the Bot Emulator or by sending SMS messages to a Twilio phone number.