Click on the button in the CR form to open the Applicability Matrix.The matrix opens in a pop-up window. It has a column for every DUC - Delivery Unit Class ( Project ) marked as potentially impacted.To edit the Matrix, click the “Edit Matrix” button. The matrix is locked for other users.Select the impacted TUCs - Tracking Unit class ( Car type ) by ticking the checkboxes. Click to save or cancel your changes and unlock the matrix. After the matrix is unlocked again, the pop-up must be closed by clicking the x on the top right side of the window.