When your location is set up to require pick processing but not shipment processing, you will use the Inventory Pick document to organize and record your picking activity.
You have three options for creating an inventory pick.
Create the pick in two steps by first creating a warehouse request from the source document, which acts as a signal to the warehouse that the source document is ready for picking. The inventory pick can then be created from the Inventory Pick window.
Create the inventory pick directly from the source document itself.
You can create inventory picks for several source documents at once by using the batch job.
Each of these three methods is described below.
In the case of sales orders, purchase return orders, and outbound transfer orders, you create the warehouse request by releasing the order by clicking Functions, Release (or pressing Ctrl+F11).
In the case of production orders, you create the warehouse request for the picking of components when the production order status is changed to Released or when the released production order is created.
Once the warehouse request has been created, someone working in the warehouse creating picks can see that the source document is ready to be picked and can create a new pick document from the warehouse request.
Open the 
Warehouse Pick
window.
Create a new inventory pick by clicking in the header and pressing F3.
In the header, you can select a source document for the inventory pick by filling in the Location Code and Source Document fields, and then selecting a source document in the Source No. field.
You can also select a source document by clicking Functions, Get Source Document to see a list of outbound source documents available for picking in the location. This list will include all released source documents for the location. Select the document you would like to work with and click OK.
The pick lines will fill with the lines for the source document that are ready for picking from the location specified in the header.
In the source document, which can be a sales order, purchase return order, outbound transfer order, or production order, click Functions, Create Inventory Put-away/Pick.
On the Options tab of the Create Invt. Put-away/Pick request window, place a check mark in the Create Pick field. If you would like to create a pick list, place a check mark in the Print Document field.
Click OK. The inventory pick will be created, and if you placed a check mark in the Print Document field, the pick list will be printed.
To work with the inventory pick just created, click Inventory, Inventory Picks, Pick, List, and select the appropriate pick from the list.
Open the Create
Invt. Put-away / Pick window.
On the Warehouse Request tab of the request window, use the Source Document and Source No. fields to filter on certain types of documents (to, for example, create picks only for sales orders) or ranges of document numbers.
On the Options tab of the Create Invt. Put-away/Pick request window, place a check mark in the Create Pick field. If you would like to print a pick list, place a check mark in the Print Document field.
Click OK. The inventory picks will be created, and if you placed a check mark in the Print Document field, the pick list will be printed.
To work with the inventory picks just created, click Inventory, Inventory Picks, Pick, List, and select the appropriate pick from the list.
Picking Items with Inventory Pick