A method for compensating for the failure of an element in a phased array antenna assembly, the method comprising the steps of: a) generating a post-failure composite pattern from signals received by respective elements in the phased array antenna assembly after failure of an element of the phased array antenna assembly; b) comparing the post-failure composite pattern to a standard composite pattern generated prior to the failure to assess necessity for remedial action; c) if remedial action is necessary, assuming an initial value for at least one parameter associated with each element; d) if remedial action is necessary, performing optimisation on the parameters to generate a modified post-failure composite pattern which approximates the standard composite pattern; e) if remedial action is necessary, applying the optimised parameters to base settings for the phased array antenna assembly; and f) continuing with operation of the phased array antenna assembly; wherein the step of performing optimisation on the parameters comprises the steps of: i) generating the modified post-failure composite pattern based on the optimised parameters; and ii) comparing the modified post-failure composite pattern to the standard composite pattern to assess whether acceptable performance is achieved; characterized in that: the generating step a) comprises generating a post-failure curve of antenna pattern difference/sum ratio (Δ/Σ) plotted against offset angle (α) for the entire phased array antenna assembly; the comparing step b) comprises comparing the post-failure Δ/Σ curve with a standard Δ/Σ curve generated prior to the failure, in addition to assessing necessity for remedial action; the generating step i) comprises generating a modified post-failure curve of antenna pattern difference/sum ratio (Δ/Σ) plotted against offset angle (α) for the entire phased array antenna assembly; and the comparing step ii) comprises comparing the modified post-failure Δ/ Σ curve with the standard Δ/Σ curve generated prior to the failure, in addition to assessing whether acceptable performance is achieved. a) generating a post-failure composite pattern from signals received by respective elements in the phased array antenna assembly after failure of an element of the phased array antenna assembly; b) comparing the post-failure composite pattern to a standard composite pattern generated prior to the failure to assess necessity for remedial action; c) if remedial action is necessary, assuming an initial value for at least one parameter associated with each element; d) if remedial action is necessary, performing optimisation on the parameters to generate a modified post-failure composite pattern which approximates the standard composite pattern; e) if remedial action is necessary, applying the optimised parameters to base settings for the phased array antenna assembly; and f) continuing with operation of the phased array antenna assembly; wherein the step of performing optimisation on the parameters comprises the steps of: i) generating the modified post-failure composite pattern based on the optimised parameters; and ii) comparing the modified post-failure composite pattern to the standard composite pattern to assess whether acceptable performance is achieved; characterized in that: the generating step a) comprises generating a post-failure curve of antenna pattern difference/sum ratio (Δ/Σ) plotted against offset angle (α) for the entire phased array antenna assembly; the comparing step b) comprises comparing the post-failure Δ/Σ curve with a standard Δ/Σ curve generated prior to the failure, in addition to assessing necessity for remedial action; the generating step i) comprises generating a modified post-failure curve of antenna pattern difference/sum ratio (Δ/Σ) plotted against offset angle (α) for the entire phased array antenna assembly; and the comparing step ii) comprises comparing the modified post-failure Δ/ Σ curve with the standard Δ/Σ curve generated prior to the failure, in addition to assessing whether acceptable performance is achieved. i) generating the modified post-failure composite pattern based on the optimised parameters; and ii) comparing the modified post-failure composite pattern to the standard composite pattern to assess whether acceptable performance is achieved; the generating step a) comprises generating a post-failure curve of antenna pattern difference/sum ratio (Δ/Σ) plotted against offset angle (α) for the entire phased array antenna assembly; the comparing step b) comprises comparing the post-failure Δ/Σ curve with a standard Δ/Σ curve generated prior to the failure, in addition to assessing necessity for remedial action; the generating step i) comprises generating a modified post-failure curve of antenna pattern difference/sum ratio (Δ/Σ) plotted against offset angle (α) for the entire phased array antenna assembly; and the comparing step ii) comprises comparing the modified post-failure Δ/ Σ curve with the standard Δ/Σ curve generated prior to the failure, in addition to assessing whether acceptable performance is achieved.