SKUs page under the product menu lists all the product variants (SKUs) from your Shopify store. 

In addition to the Product image, SKU code, product description and selling price (which are synced from Shopify) the listing also shows the following additional fields:

Product ClassThis is the ABC-XYZ class of the product which is automatically estimated and updated based on sales trends. Hovering the mouse on the field it displays the short description of the Product Class.
Products without much sales data would show a blue badge instead of the product class signifying that its a new product.
Cost Price (editable field)
This is the per unit cost of the product, i.e. the price you pay to buy the product from your supplier.  
Minimum Order Quantity (editable field)
Some suppliers have restrictions on the minimum quantity you should order for certain products. Use this editable field to update the value, in case there is no such limit leave the default value as 1. 
Pre-pack quantity (editable field)Certain products only comes in packs of multiple quantities and can only be ordered in their multiples. In such cases you this field to update the pre-pack quantity, otherwise leave the default value as 1.
Lead Time in Days
(editable field)
This is the number of days it takes for the shipment to reach your warehouse from you supplier after you have placed a purchase order. Please make sure to include time taken for administrative and processing task to capture the actual lead time.

Edit SKU Attributes

These 4 editable fields are important for accurately creating replenishment suggestions and Purchase orders,so please make sure to update them correctly for each product. 

(Functionality to bulk update these fields via spreadsheet upload is planned and would be available in a future release.)

Assign / De-assign Suppliers

You can assign a product to 1 or more suppliers by clicking on the "Factory" icon against the SKU. This takes you to a screen listing all suppliers present in your system.

Click on the supplier name to select or deselect. For assign multiple supplier press control key and click the suppliers. Once all suppliers that needs to be assigned to the product are selected click save.

Click the below link to access documentation on Sdemand forecast.

SKU Demand Forecast