Many dairy farm managers are facing decisions about how to manage changes in their industry. Estimating the costs and returns associated with these management decisions is difficult, given the complex systems interactions that exist (e.g., a change in a ration may affect milk productions levels, cropping systems and machinery use, cow reproduction and replacement rates, etc.). The Sustainable Dairy Systems Manual and Software was developed to assist dairy farm families in analyzing management decisions. The manual is more than 600 pages long, and includes chapters on site selection and preparation, information management, livestock feeding and housing, forage production, milking facilities, and animal waste management. The software includes computerized worksheets from each chapter to estimate the long-run, economic cost for a specified dairy production system. It also can be used to determine capital investment requirements for new facilities or herd expansion; to examine labor and land requirements for new grazing systems; or to estimate the economic costs and benefits of a waste management system, to name a few example applications. All worksheets are linked, so a change in one worksheet may affect several others, reflecting the systems interactions of dairy production. The software and manual is available to farmers, consultants, and educators. It was developed by a 25-member team of agricultural specialists and agents from the University of Tennessee and University of Kentucky. The 2-year development project was funded in part by the Southern Region SARE program.