Bottom-Up Design is defined as a design in which the designer is provided with all of the needed information to create the part to a reasonable level of accuracy and precision.
Access the copy to assist you in creating your own models and drawings. Don't forget to make a copy of the Title Block Template before making drawings of your parts.
Top-Down Design is defined as a design in which the design is able to look "down" onto the design to create a part using the existing geometry to ensure a reasonable level of accuracy and precision. Using the existing geometry allows the user to also create the part "In-Context" or in conjunction with the existing part.