Why is there difference between DDG and DDPG of AMM for maintenance procedure

[DongJoon Choi]

My question is Why the maintenance procedures in DDG and DDPG of AMM part2 is different, and although DDG requires only a operation action(O), Why does DDPG ask for a maintenace action?

B737's DDG has both operation procedure(O) and mainteance procedure(M).
DDPG of AMM part2 also have a maintenace procedure and most procedures in DDG and DDPG OF AMM part2 for maintenance action are almost the same but not exactly the same. WHY?

In addtion, some maintenance actions(M)required by DDG do not include a procedure but DDPG of AMM part2 shows the procedure.

For example, B737-800's DDG 22-9 requires a maintenance technician to verify that both speed trim systems operate normally and advise flight crews that both systems have been tested. However it do not show a procedure to verify the systems work properly although DDPG shows the procedure

Also, DDG 30-4 shows that to verify a engine anti-ice valve operates correctly, only flight crews(O) check the valve by using EGT,
although DDPG of AMM part2 requires maintenance people to check the valve with EGT as well. There is not any reference to (M) in DDG 30-4

Company's MELs are made with MMEL and DDG.
Many maintenance mechanics offen refer to only MEL to defer maintenance because they believe that it includes all required
maintenance actions(M)

I think it can cause mechanics to miss procedures required by DDPG of AMM part2 and spend more time seeking a procedure in DDPG, NOT in DDG, when deferring maintenance.http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/wink2.gif
How do you think??

[Nightrider]

The DDG is supposed to be a duly certified guide (Respective CAA) and issued by the FlightOps department based on the manufacturers Master List, which in turn is certified by the manufacturers CAA, and available to the people at the pointy end of the tube.
The DDPG is a maintenance issued item and has no relevance to any pilot. Discrepancies need to be sorted out on higher level and not on ramp-engineer / pilot level.