asychronous call of wcf service when sychronous of service is know

public int ExecuteSSISPackage(string ServerName,string UserID,string Password,string tpackageName,string tPackagePwd,List<parameters> tParams)
        {

            ServerConnection svcCon = null;
            JobServer js = null;
            string jobName = string.Empty;
            JobCategory jc = null;

            try
            {
                
                                //serverName = Properties.Settings.Default.ServerName;
                svcCon = new ServerConnection(ServerName, UserID, Password);
                Server svr = new Server(svcCon);
                
                //WriteTrace("Connected to {0} {1}", svr.InstanceName, svr.Information.Version);
                +" "+ "Information "+svr.Information.Version.ToString());
                js = svr.JobServer;
                jobName = "dtexecRemote_AM_job_" + Guid.NewGuid().ToString();
                jc = new JobCategory(js, "dtexecRemote");
                jc.CategoryType = CategoryType.LocalJob;
                jc.Refresh();
                if (jc.State != SqlSmoState.Existing)
                {
                    jc.Create();
                }

                Job job = new Job(js, jobName);
                job.Category = "dtexecRemote";
                job.Create();
                try
                {
                    job.ApplyToTargetServer(svr.InstanceName);

                    JobStep step = new JobStep(job, "run package");
                    string cmd = Environment.CommandLine;

                                                        
                    //cmd = @"/sq AM_RemotePackage /De ""K1PG"" /set \package.variables[AILevel1ID].Value;" ;
                    


                     cmd = @"/sq "+tpackageName+@" /De """+tPackagePwd+@"""" ;
                     StringBuilder  sbAppendParams = null;
                     sbAppendParams = new StringBuilder();
                     foreach (Parameters paramlist in tParams)
                     {
                         if (paramlist.ParmeterValue.ToString().Trim() == string.Empty)
                         {
                             paramlist.ParmeterValue = "''";
                         }
                         Utility.WriteLog("Reading Parameters of PackageName :"+tpackageName.ToUpper()+"\n");
                         Utility.WriteLog("ParamaterName :" + paramlist.ParameterName.ToString() + "  " + "ParameterValue :" + paramlist.ParmeterValue.ToString()+"\n");
                        sbAppendParams.Append(@" /set \package.variables["+paramlist.ParameterName.ToString()+"].Value;"+paramlist.ParmeterValue.ToString());

                    }

                    cmd = cmd + sbAppendParams.ToString();


                    if (cmd == "")
                    {
                        return 1;
                    }


                    //WriteTrace("Job Step Command: " + cmd);
                    Utility.WriteLog("Job Step Command: " + cmd);
                    step.Command = cmd;
                    step.SubSystem = AgentSubSystem.Ssis;
                    step.OnSuccessAction = StepCompletionAction.QuitWithSuccess;
                    step.OnFailAction = StepCompletionAction.QuitWithFailure;
                    step.Create();


                    //run the job
                    job.Start();
                                      Thread.Sleep(TimeSpan.FromSeconds(1));
                    job.Refresh();

                    //check the status of the job and loop while the job is running
                    while (job.CurrentRunStatus == JobExecutionStatus.Executing)
                    {
                        Thread.Sleep(TimeSpan.FromSeconds(2));
                        job.Refresh();
                    }


                   JobHistoryFilter hf = new JobHistoryFilter();
                    hf.JobID = job.JobID;
                    DataTable history = js.EnumJobHistory(hf);
                    history.TableName = "JobHistory";

                    System.IO.StringWriter sw = new System.IO.StringWriter();
                    history.WriteXml(sw);
                    //WriteTrace(sw.ToString());
                 
                    if (outcome == CompletionResult.Succeeded)
                    {
                        //WriteTrace("Package Execution Suceeded");
                            return 0;
                    }
                    else
                    {
                    }
                    

                }
                               
                finally //drop the job
                {
                    js.DropJobByID(job.JobID);
                }
                
            }</parameters>