Described herein is a computer implemented method for maintaining a plurality of issues, each issue having an associated rank value, the rank values of the plurality of issues defining an order of the plurality of issues. The method comprises receiving a rank operation request to change the rank of a subject issue; determining relevant issues to the rank operation request; and attempting to acquire locks on each of the relevant issues. In response to successfully acquiring locks on each of the relevant issues a new rank value for the subject issue is calculated and saved.