How to Enforce WIP/MES move transction Sequentially forward

Hi,

We have an requirement to enfore the MES move transaction sequentially forward to next sequence. Need your inputs on the same..
System should not allow backward or reverse movement. Below is the illustration

Op10 - 0 quantities exist (i.e.all the quantities are moved to Op20)
Op20 - 100 quantities exist

Now system should enfore the next move to Op30. It should restrict to move back to Op10.

Note: we have set the MES parameter value 'Enforce Sequential Move' = Yes but still the system allows for backward movement.

Thanks in Adavnce for your input

Kamaraj