Herein this links you'll find two formats for i) inward and ii) outward-
Format For Material Inward Register.Doc
Format For Material Outward Register.Doc
If you'll find both separate registers are convenient to you, the same can be used with suitable modifications.
I would suggest a separate register, both these formats combined in side-by-side two pages wherein you can record both inward as well as outward entries. This'll help you to identify which are all came-in, went/sent out & what are remaining-in-progress at any point of time. In case of any confusion or enquiry from customer/shop side items could be easily identified. Serialize each entry, date-wise and round them-off using 'red ink' marker as and when sent out. This'll help you to identify/list them out 'as in-progress'.
Care should be taken to attach a irreplaceable tag to each unit coming-in with Customer code & product code/date-in which can be verified while they are sent out so that wrong ref. could be detained at the gate & checked before they are passed out. Also while they are sent out record- data of vehicle, driver's/receiver's sign should be obtained (including date & time). I hope, needless to say every 'outward entry' should have a cross reference to your 'GST' job work invoice. If the Security is provided with PC you should input data in the same format which can be shared with Shop Managers & Invoicing sections.