How to create a combination of parallel-Sequential workflows using Visual studio 2010 in sharepoint 2010

Question

Hi To All..



I want to create a workflow which is a combination of  Parallel-Sequential Workflow(Appraisal Workflow for a employee) using Visual studio 2010  in share point 2010




The only constraint is we have to use completely Visual Studio only
I dont want to do my work others.I need guidance to create a work flow using visual studio only

The main theme of workflow is to  grant a  appraisal to a employee to a particular department


Level 1: The employee fill the form and the workflow


Level 2: The form reaches the appraisal department (one of the manger out of 4 managers approves the employee workflow)


Level 3: once the manager from the appraisal department approves the workflow is assigned the the current project manager


level 4: once the current project manager approves the workflow assigned to Delivery Head


Level 5: Once the Delivery Head approves is goes to Hr Dept(a group of 5 managers)


level 6: once the One of the hr manager approves the workflow it will re assigned to Delivery Head


level 7: once the Delivery head approves the workflow it will assigned to CEO


level 8: once the CEO approves the workflow,The Workflow is completed and Status is sent to Employee whether his appraisal is accepted or rejected




Please help me to find a solution fro this




Thanks in ADVANCE..