A process for manufacturing a laminated glazing unit so that it withstands predetermined stresses, the laminated glazing unit comprising at least one substrate having a glass function (3, 5) of given chemical composition and at least one polymer interlayer of given chemical composition (c i), characterized in that it comprises steps in which: - a reference laminated glazing unit is identified that withstands said predetermined stresses and that comprises at least one substrate and one interlayer having the same chemical compositions as those of the laminated glazing unit to be manufactured; - the tear strength (J c-ref) of the interlayer of the reference laminated glazing unit, the interlayer thickness (e i-ref) of the reference laminated glazing unit and the substrate thickness (e g-ref) of the reference laminated glazing unit are determined; - using a graph (C 1, C 2, C 3, C 4) representative of the minimum interlayer tear strength (J c-min) required so that any given laminated glazing unit, comprising at least one substrate and one interlayer having the same chemical compositions as those of the laminated glazing unit to be manufactured, withstands said predetermined stresses, as a function of the interlayer thickness (e i) of said any given laminated glazing unit and/or of the substrate thickness (e g) of said any given laminated glazing unit, a combination of optimum values (e i-opt, e g-opt) of the interlayer thickness and of the substrate thickness is deduced which corresponds to a value of the minimum required interlayer tear strength equal to the tear strength of the interlayer of the reference laminated glazing unit (J c-min = J c-ref); - the laminated glazing unit is sized with a chosen interlayer thickness (e i-dim) greater than or equal to said optimum value of the interlayer thickness (e i-opt) and a chosen substrate thickness (e g-dim) greater than or equal to said optimum value of the substrate thickness (e g-opt). - a reference laminated glazing unit is identified that withstands said predetermined stresses and that comprises at least one substrate and one interlayer having the same chemical compositions as those of the laminated glazing unit to be manufactured; - the tear strength (J c-ref) of the interlayer of the reference laminated glazing unit, the interlayer thickness (e i-ref) of the reference laminated glazing unit and the substrate thickness (e g-ref) of the reference laminated glazing unit are determined; - using a graph (C 1, C 2, C 3, C 4) representative of the minimum interlayer tear strength (J c-min) required so that any given laminated glazing unit, comprising at least one substrate and one interlayer having the same chemical compositions as those of the laminated glazing unit to be manufactured, withstands said predetermined stresses, as a function of the interlayer thickness (e i) of said any given laminated glazing unit and/or of the substrate thickness (e g) of said any given laminated glazing unit, a combination of optimum values (e i-opt, e g-opt) of the interlayer thickness and of the substrate thickness is deduced which corresponds to a value of the minimum required interlayer tear strength equal to the tear strength of the interlayer of the reference laminated glazing unit (J c-min = J c-ref); - the laminated glazing unit is sized with a chosen interlayer thickness (e i-dim) greater than or equal to said optimum value of the interlayer thickness (e i-opt) and a chosen substrate thickness (e g-dim) greater than or equal to said optimum value of the substrate thickness (e g-opt).