If purchasing documents correspond to a key combination for which a purchase grid exists, (for example, Material - Vendor - Purchase Organization), the procurement transaction will be based on this key combination. You can then only choose from the grid values permitted in the purchase grid. The system also transfers the additional information entered in the grid control data is transferred to the purchasing documents. In Customizing you can individually define key combinations and their validity, access sequences, grid condition types, as well as the grid determination procedure.

1. Establish Global Settings.
   In the global settings, if you set the indicator PR grd det. act the grid determination is active for purchase requisitions. Otherwise the master grid is used. For contracts, if you do not set the Use Master grid indicator, the grid determination will be active. In addition, you can individually specify for the various purchasing document types whether the basis for the grid determination should be the creation date or the delivery date, and in the case of contracts, the contract start or end date.
2. Define Field Catalog.
   In the field catalog you define the fields that should be available for selection in the condition tables (for example, Material, Plant, Purchasing Organization).
3. Define Condition Tables
   In condition tables you specify which fields the grid determination should take into account when selecting a certain key combination. We recommend that you do not change the AFS standard system condition tables. If you want to define your own condition tables, choose a number between 501 and 999. Create the table with or without a validity period, enter an appropriate description for the table, select the permitted fields for the table, and then generate your new condition table.
4. Define Access Sequences for Condition Tables
   With the access sequence you determine in which sequence the AFS system searches through the condition records to find a valid condition record. In the table field AcNo (access sequence number) enter the sequence in which the system should consider the corresponding condition record and in so doing determine the search strategy. Then enter the key combination. In the field Requirement, define whether the access sequence should be valid for purchase requisitions (102), purchase orders (101), or for both (blank). We recommend that you do not change the access sequence for the master grid MGRD.
5. Define the grid condition type and assign it to an access sequence.
   With this assignment you determine that certain access sequences (such as PGRD - purchase grid) should be valid for certain grid condition types (such as PGRD - purchase grid). You can also determine the assignment and validity periods for grid condition types. We recommend that you do not change the AFS standard system grid condition types.
6. Define the grid determination procedure and assign it to a grid condition type.
   Here you define a procedure (for example, MM0001) and assign a grid condition type to it (such as PGRD). Via the grid condition type you assign an access sequence to the procedure. Via the procedure that you enter for each AFS material in the AFS Basic data view of the material master, you thus control in which hierarchical sequence the system seats for valid condition records for this material and which purchasing documents are included in the grid determination. We recommend not changing the procedure MM0001 in the AFS standard system.