Where does the quest for good picking performance begin? Before talking about picking methods or the different technology available it is important to look at the way a sales order is handled. Key to an effective picking strategy is a smooth order process. And where more than one IT system is involved in this they must communicate well in order to facilitate that process.
In some business operations, for example a 3PL company, sales orders may be entered manually or electronically direct to a WMS. In most other cases they are captured (from web or telesales etc) and recorded into other systems. Typically this will be an ERP or accounts based sales order processing (SOP) function, usually working in tandem with an integrated stock control system. A common issue with first time WMS users is how to make these systems work in sync with each other.
Firstly any promise or reservation of stock given to the customer must be based on the most accurate stock information available. This means that stock figures used in any order capture system must be updated via interface from the WMS in, or as near as possible to, real time. This is because the WMS holds the true ‘physical’ stock figure. Any other figure is theoretical, usually fluctuating and frequently prone to inaccuracy.
So for an immediate delivery the SOP system knows stock is definitely available and the promise can be fulfilled. Where stock is being reserved for a future delivery it will also know, with visibility of current stock, orders received and (possibly) forthcoming orders, whether stock reorder is required to meet future promises while ensuring interim orders to be satisfied sooner are not left short.
Secondly the order should be transferred immediately to the WMS. Apart from obvious reasons of delivery urgency, visibility of all pending orders is key to efficient logistics planning. Most importantly orders should be transferred electronically in order to reduce errors, paperwork and admin time.
Once orders reach the WMS they can be planned according to multiple criteria, and when ready for picking the WMS will allocate stock to them. If stock is unavailable there is no need to refer back to a SOP system as the stock figures will only correspond to those held in the WMS. And should last minute stock arrive, as the ‘physical’ receiving point the WMS will know this and can execute a cross dock movement to satisfy the order.
So ultimately, after orders leave the SOP system (save for amends made before WMS processing) the WMS alone is responsible for their fulfilment. Orders will sometimes be short picked for whatever reason, and in these cases internal policy will determine whether to despatch short or delay orders pending stock availability.
Where short orders are despatched the WMS can advise the SOP of this at the end of the process, retaining or deleting the residual order as practice dictates.
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