## Sub-Material Handing with E90

E90 defines the Substrate object state model as following:

![Substrate Object State Model](howto.images/e90SubstrateObjectStateModel.png)

For MES Material handling we can use the standard Material System State Model for the Sub-Material Process.

Currently the following transactions of the state model should be used to trigger the changes using the following workflows:

| Transaction | Transaction Description | Workflow                                  | Action Description
| --- | ---------- |------- |------------ |
| E90 -> 11  |  Needs Processing to In Process | OnSubstrateProcessStarted | Tracks In Sub-Material on MES and updates state on EI level |
| E90 -> 12  | In Process to Processing Complete | OnSubstrateProcessCompleted | Tracks Out Sub-Material on MES and updates state on EI level |