Agile and DevOps recommend that testers should shift to the left in the familiar chain "analysis> design> develop> TEST> release", but what does this mean? Is this the only right approach? 

Shifting of testing to the left or right can satisfy different needs and improve various aspects. But how should you understand if changes need to be made? 

When management of testing, shifting the test phase to the left or right can be like a car's transmission shift and helping you get to where you need to be.