test approach- test lead is mentioning the list of the TRM 
columns which have been finalised by the project manager.
TRM-test responsible matrix- mapping between various 
testing issues and develpment stages.
Test strategy- its  a company leve document prepared by the 
QA n d aim of QA is testing approaches to acheive testing 
objectives..n he maintaind d budget of whole project.

Test strategy is how to approach your  project and its 
guide for your project and which approach to be followed  
and which methods to be followed  to be explained strategy
Approach is a idea of  your  project it means I will tell u 
contents 
Like risks & environment  what the business logics how to 
approach the critical time 

System integration testing 
Testing on each component and integrate the all components 
and executed all components in your system (your module 
components only)