Hello Walter,
I think it is possible to scrap the material in fast way without any development or very simple development. You need to do some of the configurations. Please follow below steps.
(1) Create new IM movement type by coping 551 in OMJJ.(for ex- 951) Go to field selection (from 201)/batch search tab. Double click your entry of new movement type. Go to warehouse management view and make "WM storage bin" as a required entry.
This movement type will make sure that you will get warehouse storage type and bin entry as mandatory entry when you will use MB1A- with your new movement type
(2) As a first step of scrap entry, what you have to do is identify scrap material. Select your storage unit and flush out it to some interim bin. May be you can put all your scrap material in special interim storage type which would be copy of storage type 999. You can mark the bin as SCRAP. Else you have choice to use same storage type 999 with new bin as SCRAP. You can use movement type 999 or 551 for this with transaction code LT01 or LT10 for mass transfer of scrap material from your bin.
(3) Now your situation is, all the scrap materials are in interim storage type lets say 999 without having storage unit. What you need to do is, run transaction MB1A with your new movement type as per step 1 giving storage type and bin as in step 2. That's it! All your stock will be removed same time from IM and WM.
(4) There is another method by which you can avoid using IM transaction. This is physical inventory method. But the business need to agree with this. The process is, follow step no 2 above and then use LI21 transaction to clear IM stock. You can use background job for LI21 with proper variant.
All the best!!
Thanks
Milind