def execute_cmd(self, *args, **kwargs):
        """Execute a given hpssacli/ssacli command on the controller.

        This method executes a given command on the controller.

        :params args: a tuple consisting of sub-commands to be appended
            after specifying the controller in hpssacli/ssacli command.
        :param kwargs: kwargs to be passed to execute() in processutils
        :raises: HPSSAOperationError, if hpssacli/ssacli operation failed.
        """
        slot = self.properties['Slot']
        base_cmd = ("controller", "slot=%s" % slot)
        cmd = base_cmd + args
        return _ssacli(*cmd, **kwargs)