– E.g. 30 days, 60 days 如30天,60天
• This often leads to excessive inventory for fast moving SKUs and, sometimes, insufficient inventory for slow moving SKUs • 这通常会导致对流动较快的品类导致库存过大，而对于流动较 慢的产品来讲，导致库存不足；
Gather inputs
Load model
Run model
Export results to planning system
Execute Replen. Process (DRP)
Continuous evaluation of input parameters
Recent Model Enhancements
T
Time 周期
Inventory in the Supply Chain 供应链中的库存
Type类型
Anticipation Stock 预期库存
Use目的
To cover future demand. Avoid or delay Capital expenditure.
Drivers驱动器
• Product transitions产品 切换 • Technology transitions
– 99.9%
• • • • 1 every 1,000 replenishment occasions 1 every 1,000 shipments from Jax/Irl 1 every 20 years (weekly shipments) 1 every 7 years (three shipments per week)
• FOQ • Transportation lead times • QA cycle time • Number of SKUs & Lines • Changeover time • Lot sizing • Delivery freq. • Total demand • Lead time • Demand variation • Manufacturing reliability • QA Loss/Delay
Safety Stock
Statistical Safety Stock Model SIPOC
SUPPLIERS
-Affiliates -Customers -IM
INPUTS
-Service level -Lead time -Order frequency -Avg demand (per SKU) -Std deviation (per SKU)
Periodic Review Inventory Model 阶段性库存模型
Inventory on hand (in units)在手 库存 Place order 下单 Place order 下单
Place order 下单
Safety stock 安全 库存
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L
T
L
T
L
Stock out 库存亏空
Safety Stock
Japan Review January 2003
Safety Stock
• Safety stock is buffer inventory to protect against fluctuations in demand or supply during the order lead time • 安全库存是用于订单交期内需求或供应发生波动时的缓冲库存; • Typically safety stock is set to a “comfortable” level for all SKUs • 通常,安全库存是对所有品类设计一个所谓的舒适的水平;
• Analysis of low versus high variability SKUs • Low Variability
– Standard deviation is less than 50% of demand
• Ability to specify different service levels • Use one % for high variability items • Use a different % for low variability items
Service Level
• Probability of No Backorders
– Percentage indicates the statistical chance of backorder every x replenishment occasions
• 99.99 = 1 every 10,000 • 99.9 = 1 every 1,000 • 99.0 = 1 every 100
PROCESS
Statistical Safety Stock Model
OUTPUTS
-Safety stock (per SKU) -Total inventory req.
CUSTOMERS
-Affiliates -Customers -Global Log. Planning -Finance
Model Enhancement
Using Shipping data from August 30, 2002 to December 18, 2002 Implemented
JPN Statistical SafeCustomer Service Measure Desired fill rate Probability of no backorders (low variation) Probability of no backorders (high variation) Order Interval (days) Lead time (days) Probability of no backorders
Inventory Targets
Pipeline Stock Product in transit or work in process
Cycle Stock
Function of lot sizing or ship quantities To buffer against uncertainty in demand or supply