Chapter 4 Warehouse management systems Flashcards
The disadvantages a of standard WMS.
Disadvantages
(1) The standard WMS cannot always be configured to the desired method of working and needs to be amended with customized enhancements before implementation.
(2) Most failed package installation projects are because of too many custom enhancements.
(3) Problems are encountered later on when the company wants to upgrade its system. WMSs with many customizations is difficult to upgrade.
Name and describe add-on (complementary) modules to the WMS.
Add-On Modules:
i. Customs Management – A customs module supports the customs declarations for goods in the DC and keeps an accurate view on inventories under customs control.
ii. Billing of Logistics Services – 3rd party warehouses charge clients for services provided (e.g., a fee for receiving a pallet or a weekly fee for storing a pallet). Also, private warehouses may charge their internal clients. The billing module registers which services have been provided to each individual client and generates periodic client invoices.
iii. Web Portal – Clients, suppliers, customers, can see the status of warehouse activities such as “Has the order already been shipped?”, “How much inventory is still available?” A web portal makes this information available via the internet. It can be used to enter information to reserve a timeslot at the docks or pre-announce the contents of a delivery. Only authorized users can access the information.
iv. Dock and Yard Management – The WMS may control truck movements in the yard. The dock and yard management module decides at which dock a truck should load or unload or directs a truck to a parking spot to await its time window at the dock. The module may also register inventories held in trucks in the yard.
v. Slotting – A slotting module assigns products to pick locations (pick slots) based on product characteristics such as turnover velocity, weight, volume, etc. Since assortments and demand patterns change, the slotting module does a periodic update of the preferred pick locations of products.
vi. Management Information – During the day, the WMS registers detailed information on activities that are performed. Useful management information can be extracted from the WMS which analyzes and reports such information. These modules allow users to create their own indicators from available data.
vii. Labour Management – A labor management module computes the number of man hours for a given set of orders. This estimate is used to plan the required number of operators in advance. The computations use detailed standard times for activities, so-called engineered labor standards.
viii. Inventory Management – Not a WMS function although the DC is constantly amending the inventory levels, it does not decide how much inventory should be present. This is decided by the inventory control department. Often the inventory management module is contained in the ERP system. There are also specialized inventory management systems.
ix. Order Management – Many order-related activities are included in order management such as order-entry and order acceptance. Order management modules are traditionally included in the ERP system but there are also specialized order management systems (OMSs), particularly useful in operations where stock is shared among multiple warehouses. The OMS decides in a dynamic way from which site orders should be sourced, which routes to take and how long it takes to deliver the orders to the customers.
x. Finance – The WMS records the goods that have been received and shipped as well as the associated logistics services that have been provided to each client. However, the actual invoicing and accounting is left to a separate financial system or the financial module of the ERP.
xi. Transportation – A WMS is capable of planning external transportation when the routes are fixed, e.g., the truck to Germany departs each day at 3 PM. If routes are variable, then the transportation is planned by a transportation management system (TMS).
Explain the wireless devices used in real-time communication (paperless warehousing).
- Radio frequency (RF) terminals - has a screen, antenna and barcode reader and is wirelessly connected to the WMS. The WMS displays commands on the screen and the operator replies by typing responses or scanning barcodes. RF gives the WMS a real-time view of the progress in the DC.
- Voice terminals - Operators listen to commands through headsets and reply via commands spoken into a microphone. It is hands-free and time is not wasted scanning or typing on the RF terminal.
- Pick-to-light - When only one operator works in a section. Each location has a display that shows the pick quantity. After the quantity is picked, the operators push a button next to the display to confirm the pick.
- Put-to-light - like pick-to-light but used for sorting products among customer orders. Each location represents an order. The operator scans a product, and the put-to-light system shows the quantity that should go to various customer locations.
How has paperless warehousing (real-time communication) improved warehouse processes?
- It enables WMS to assign tasks to operators, taking into consideration the current location of the operator and the urgency of tasks.
E.g., the WMS can assign a pallet move to a forklift driver who just completed a task nearby, thereby minimizing empty travel time, or assign a task that is further away but more urgent. - The WMS also verifies every task in real time, reducing errors compared to paper lists.
- Administration tasks such as confirming receipts, orders and pick tasks, are performed directly on the warehouse floor making several administration functions redundant.
Rationing rules
- First come first serve.
- Even allocation.
- Even allocation relative to the ordered quantities.
- Important customers served first.
What events affect inventory levels.
- Inventory discrepancies - Receiving errors or theft for example cause actual inventory levels to differ from the registered inventory in the WMS. Inventory should be counted regularly and if it differs adjustments should be made accordingly.
- Damage - Damaged products cannot be shipped to customers and will be thrown away, shipped to a repair center or send to a junk dealer.
- Expiration - Perishable goods have a latest goods issue date - e.g., goods should leave the DC at least 8 weeks before best-before date. If it can’t be shipped before that date it will go to an alternative destination or be disposed of.
- Blocking - Products can be blocked from shipping for different reasons. One reason is it needs to be tested. Only when the test results are positive will the block be lifted, and the product be made available for shipping.
Difference between product attributes and inventory attributes.
Product attributes define a product. They apply to every unit of a product.
Inventory attributes relate to the goods that are physically present in the distribution center. E.g., lot numbers, serial numbers and expiry dates.
Inventory attributes can differ between units of the same product while product attributes stay the same.
Name different product attributes (product master data/product definitions).
- Product number
- Product description
- Product group
- Price
- Preferred supplier
- Temperature class, e.g., ambient, chilled, frozen.
- Hazardous material classifications.
- Dimensions (length, width, height) per individual item, case and pallet.
- Weight
- Pack configuration, i.e., pieces per pallet, pieces per case, etc.
What is a WMS?
A software system that controls the activities within the DC. The system know which goods are to be received and shipped. It determines which tasks need to be performed to process the goods and sends commands to human operators and automated material handling systems to execute tasks. The system also captures relevant data on orders, shipments, inventory warehouse layout, warehouse staff, vehicles, customers, suppliers and activities in the DC and so on. This ensures the tracking and tracing and quality of warehouse activities.
Advantages of standard WMS.
- High flexibility - redesigning processes can be achieved relatively easily by reconfiguring parameters and business rules. This is much more complex for custom-build systems.
- Quick implementation - users configure the options in a standard system instead of a software code having to be customized from scratch. This saves a lot of time.
- Ongoing development - standard systems become better over time as new features are introduced through system updates. The system is also kept up to date with the latest technological developments.
