Picking Automation for Order FulfillmentPosted: 04/12/2011
If you are processing high volumes of orders in your warehouse, you are probably also using too many pickers to pick and pack the orders you get. Humans are not robots, so we make mistakes. This is also valid for your pickers too. But there are ways to reduce the number of mistakes they make while picking. In this article I will try to cover some of the most common techniques that can be used to increase your picking performance and accuracy.
Of course the picking process needs products to be in stock. But typically a small startup e-commerce operation would keep no stock at all and purchase items from suppliers as the orders arrive. A little growth in number of orders will force the startup to keep stock for most popular products. Or you can be a large e-commerce operation with many products from different suppliers, this time you will again keep your own stock to maintain profitability and shorter delivery times and at the same time you will probably have supplier managed warehouses.
In any of these cases, whenever you start keeping stock, you will start having picking problems.
A typical scenario for high volume order fulfillment with high average number of lines per order is that your pickers work at the picking zone and you also have another team who replenish the picking zone. But both teams are open to make mistakes. A mistake in picking will cause many complications like order being returned and sent back again to customer. This will not only generate additional costs for you but it will also effect your credibility in a bad way. Therefore, we do not want this. To prevent this from happening, you probably also have another zone where you make some quality control to make sure the orders are picked correctly. More manpower, more costs.
As the number of orders increases, you will soon find yourself in a situation where your picking accuracy is starting to hit the floor. To workaround this issue, you will start investing on more people and have a larger quality control team. But realize that, you are now in a deadly cycle here. So to break this cycle you need some methods to help you. One of them is to have a good Warehouse Management Software. But WMS alone will not help you as you are still 100% dependant on humans.
Let there be lights!
Installing LED indicators to help your pickers to correctly find where the products are located is one of the most common techniques. There are several ways you can use light indicators in your operations:
Pick to Light
Pick to Light (PTL) systems are usually installed inside a picking zone or over a picking line. When an order is fed into the system, all required positions for the products in that order lights up and each light unit shows the number of products the picker should pick. After picking the required quantity, picker simply presses a button on the unit to indicate that he is done picking with that product. As soon as he turns all the lights off, this means that the picker is done with picking that specific order and he pushes the carton to next station, the lights for next order turns on for him.
Put to Light
In a Put to Light system, which is the reverse of Pick to Light, picker is provided with batches of products in a trolley or in boxes over a conveyor belt and picker simply matches the products with the orders. The most common technique for matching is to scan the bar codes of products in trolley and light up the orders which should contain that certain product.
The newest light units are designed to be wireless and therefore they allow you to install easily with not much cabling. Light units are controlled with a controller PC which automates the order picking queue and controls the lights. The cost of the system depends on the number of light units you need.
Here is a video for a sample PTL operation :
Let there be sound!
One of the latest innovations in order fulfillment is Voice Picking. Since it is new and a little expensive, it is still not widely used in warehouses. Many people also refer to this as Talking Warehouse. The basic idea is to tell the picker where the product is located and how many he should pick. Many of you who are familiar with IVR systems, will realize that this is a similar system. Picker interacts with the system over a headset which includes a microphone and these are connected to an RF handheld device. Picker listens the commands coming from the system and acts accordingly then confirms the action by talking to the system. This is where speech recognition comes to help. Actually it is the speech recognition that makes this system unique and expensive. Not many languages are supported by these systems, so if you are located in a non-english speaking country, it is most likely that your language is not supported so make sure to check with the vendor about the support for your language and about how soon they can deliver a solutions for you.
You can use the voice anywhere within the warehouse, either in docking, replenishment, picking or packing. Just like PTL systems, all voice units are controlled by a PC which automates the picking queue and performs the voice operations including speech recognition. The cost of implementing Voice picking is normally higher than PTL systems.
Here is a good sample video :
Pick faster with automated A-frame picking line
All of the above techniques will help you improve your picking accuracy. They can also help to increase your picking speed a little. But if you need considerable changes in your picking speed, then you need to look for other solutions. Assume you have boxed products with cubicle shapes and you have high volume of orders arriving each day. For example a large pharmaceutical distribution center. Then you have other alternatives. Using an automated A-frame type picking line is one of them. The cost of implementing automated A-frames is most likely to be higher than PTL and voice solutions.
Here is a video showing automated A-frame picking line in action :
Let there be robots!
There are also huge machines and robot arms that make the picking easy. But we are talking about ultra high costs here and complex machinery installations. One of the latest innovations I love comes from a company called Kiva Systems. They have invented a moving robot that can help you with your order fulfillment process. It is a semi-automated system that minimizes the cost of moving goods within your warehouse and also saves you space in your picking zone. This is probably the most expensive method.
Here is a video from Kiva Systems showing how the system works :
These are not the only methods you have, there are other techniques too. There can also be combination of all these methods. But I believe I have been able to give you a brief idea about how you can increase your picking accuracy and speed.