Supply Chain Glossary
Precise definitions of supply chain terminology, from EOQ to IBP, for quick reference in day-to-day work.
80 terms
ABC Analysis
A method for classifying inventory items by annual consumption value, based on the Pareto principle. Category A items are few in number but represent most of the value and warrant tight control; category C items are numerous but low-value and need only light-touch control.
Bill of Materials (BOM)
A structured list of every component, raw material, and sub-assembly needed to produce a finished item, along with the quantity of each. A BOM can be single-level or multi-level (with nested sub-assemblies) and is the foundation for MRP explosion.
Bullwhip Effect
A phenomenon where small fluctuations in end-consumer demand become larger and more volatile as they propagate upstream through suppliers and manufacturers. Root causes typically include independent forecasting at each tier, batch ordering, and lack of visibility into real end-demand.
Business Continuity Planning (BCP)
A document that predefines the processes and actions needed to continue critical business operations during a major crisis (natural disaster, infrastructure disruption, supply crisis). In supply chain, it typically includes identifying backup suppliers and alternate routes.
Capacity Planning
The process of determining whether existing production capacity (machinery, labor, shift patterns) is sufficient to execute the production plan, and if not, identifying corrective actions such as overtime, added shifts, or partial outsourcing.
Cash-to-Cash Cycle
The time it takes for capital spent on raw materials to return to the organization as cash, through production, sales, and receivables collection. A shorter cycle means less working capital is needed to run day-to-day operations.
Center of Excellence (CoE)
A dedicated internal unit or team that develops standards, tools, and best practices for a specialist domain (such as planning or data analytics) and transfers them to the rest of the organization. Its goal is preventing repeated, inconsistent reinvention of the same capability across different units.
Change Management
A structured approach to guiding people and processes from a current state to a new way of working, including communication, training, and resistance management. Many technically sound supply chain projects (such as MRP rollouts) fail due to neglected change management, not flawed technical design.
Changeover Time
The time a production line is down while switching from producing one product to another (e.g. tooling or machine setting changes). Reducing changeover time (such as via SMED methods) enables smaller batch sizes and greater flexibility.
Collaborative Planning, Forecasting and Replenishment (CPFR)
A framework for collaboration between suppliers and buyers (e.g. manufacturer and retailer) to share demand data and build a joint forecast, rather than each party forecasting independently. Its goal is reducing the bullwhip effect while improving both forecast accuracy and service levels.
Consensus Forecast
The final demand forecast reached through discussion and agreement among sales, marketing, planning, and finance during the S&OP demand review meeting. Unlike a raw statistical forecast, a consensus forecast incorporates qualitative market knowledge such as promotions or one-off events.
Consignment Inventory
An arrangement where a supplier stores goods at the buyer's location, but retains ownership until the goods are consumed or sold. This shifts working-capital risk from buyer to supplier and requires high trust and data transparency between both parties.
Contract Manufacturing
An arrangement where a company outsources the manufacturing of a product or component to an external manufacturer, while product design and brand ownership remain with the original company. Common in pharma, electronics, and food to manage fixed capital investment.
Control Tower
A centralized visibility and decision-making layer that aggregates real-time data from across the supply chain (production, warehousing, transportation, suppliers) into one unified dashboard, so disruptions can be identified and managed faster.
Cost-to-Serve
An analysis calculating the true cost of serving each customer or sales channel — including small-order handling, expedited delivery, or returns — instead of assuming a flat margin across all customers. Often reveals that some 'large' customers are actually less profitable than assumed.
Cross-Docking
A distribution method where inbound goods from a supplier are transferred directly to outbound transport with little to no long-term warehouse storage. It reduces storage cost and delivery cycle time, but requires precise timing coordination between inbound and outbound.
Cross-Functional Alignment
The degree to which different organizational functions (sales, production, procurement, finance) agree on a single plan and set of priorities, instead of each pursuing local — and sometimes conflicting — goals. S&OP/IBP cycles are the primary tool for achieving this alignment.
Cycle Counting
An inventory-accuracy control method where, instead of one full annual physical count, a subset of items is counted continuously on a planned schedule (e.g. daily or weekly). It surfaces inventory errors faster and causes less disruption to warehouse operations.
Cycle Stock
The portion of inventory held to cover normal demand between two consecutive replenishment orders, separate from safety stock. Its size is typically driven by order quantity (e.g. EOQ) and ordering frequency.
Data Governance
The set of rules, roles, and processes that manage the quality, accuracy, ownership, and access of organizational data. Without proper data governance, even the most advanced analytics or AI tools end up built on unreliable data.
Days of Inventory on Hand (DIOH)
A metric showing, on average, how many days of demand current inventory can cover. Calculated as on-hand inventory divided by average daily usage, used alongside inventory turnover to monitor inventory health.
Days Payable Outstanding (DPO)
The average number of days an organization takes to pay its suppliers' invoices. A higher DPO improves the organization's working capital, but if pushed too far, it can strain supplier relationships and future pricing terms.
Days Sales Outstanding (DSO)
The average number of days it takes an organization to collect payment from customers after a sale. A high DSO means more capital stays locked up with customers for longer, putting more pressure on organizational liquidity.
Dead Stock
Inventory items that have had no movement (sales or consumption) for an extended period and have low likelihood of future use. Dead stock ties up capital and typically needs to be managed through discounted sale, rework, or write-off.
Demand Planning
The process of forecasting future customer demand by combining historical sales data, market trends, seasonality, and sales-team input. Its output drives production, procurement, and inventory decisions, and is typically reviewed in the monthly S&OP cycle.
Demand Sensing
An approach that uses near-real-time data (such as daily store sales or incoming orders) to refine short-term demand forecasts over a horizon of days to weeks. It complements, rather than replaces, mid-term demand planning.
Demand-Supply Balancing
A stage in the S&OP cycle where demand forecast is compared against real supply capacity (production, procurement, inventory), and if a gap exists, corrective scenarios are evaluated — such as overtime, expedited orders, or managing customer expectations.
Digital Twin
A virtual, continuously updated model of a process, facility, or entire supply chain network, synchronized with real data, enabling simulation of different scenarios (such as capacity changes or supplier disruption) before real-world execution.
Distribution Center (DC)
A facility that receives goods from manufacturers or suppliers, stores them, and then distributes them to customers or stores based on orders. Unlike a traditional warehouse focused on long-term storage, a distribution center is optimized for fast throughput.
Dual Sourcing
A strategy of sourcing an item from two independent suppliers simultaneously, to reduce the risk of single-source dependence. The added cost of managing two relationships is usually justified against the reduced risk of supply disruption.
Economic Order Quantity (EOQ)
The order quantity that minimizes the combined cost of ordering and holding inventory over time for a given SKU. EOQ assumes constant demand and lead time, so in practice it's typically treated as a starting point for calculation rather than a final, fixed number.
Executive S&OP
The final stage of the monthly S&OP cycle, where senior executives review and formally sign off on the scenarios proposed by operational teams. This is the point where the plan becomes an official, organization-wide, executable decision.
Exponential Smoothing
A demand-forecasting method that weights recent data more heavily than older data, controlled by an adjustable smoothing coefficient (alpha). It reacts faster to real market shifts than a simple moving average.
First In, First Out (FIFO)
An inventory management method where the oldest stock on hand is the first to be consumed or sold. Nearly mandatory for perishable or expiry-dated goods (such as food and pharma) to prevent spoilage or expiration of inventory.
Forecast Accuracy
A measure of how closely a demand forecast matched actual realized demand, usually expressed as a percentage. The most common metrics are MAPE and bias, and tracking it over time reveals which methods or items need forecasting-model revisions.
Freight Consolidation
Combining several small shipments from different sources into a single transport load, to fill carrying capacity and reduce per-unit shipping cost. Requires precise timing coordination among different order sources so shipments are ready simultaneously.
Incoterms
A set of internationally standardized trade terms, published by the International Chamber of Commerce (ICC), that define the responsibilities, costs, and risk transfer between buyer and seller in export/import transactions (e.g. FOB, CIF, EXW).
Integrated Business Planning (IBP)
An evolution of S&OP that integrates financial planning, new product introduction, and business strategy alongside demand and supply into one unified decision cycle. IBP typically spans a longer time horizon than traditional S&OP and is tracked at the executive/board level.
Inventory Carrying Cost
The total cost of holding inventory over time — including the cost of capital tied up, warehousing, insurance, shrinkage, and obsolescence. Usually expressed as a percentage of inventory value per year, and a key input to the EOQ calculation.
Inventory Turnover
A ratio showing how many times an organization's inventory is sold and replaced over a given period, usually a year. Calculated as cost of goods sold divided by average inventory; a higher turnover generally signals more efficient use of working capital.
Just-in-Time (JIT)
A production philosophy aiming to produce and deliver exactly what's needed, when it's needed, without holding excess inventory. JIT depends heavily on supplier reliability and process stability, and is vulnerable to supply chain disruptions.
Kanban
A visual system for controlling production flow and inventory, where a card or physical/digital signal communicates actual consumption upstream, authorizing new production or replenishment only after real consumption occurs. A core tool of lean manufacturing and pull systems.
Key Performance Indicator (KPI)
A measurable metric showing progress toward a specific operational or strategic goal, such as forecast accuracy, on-time delivery rate, or inventory turnover. A useful KPI must be tied to a real decision, measurable on a regular cadence, and have a clear owner.
Kraljic Matrix
A tool for classifying purchased items along two axes — financial impact (spend value) and supply risk (number of suppliers, market complexity). It produces four categories — leverage, strategic, non-critical, and bottleneck items — each requiring a different procurement strategy.
Last In, First Out (LIFO)
An inventory method where the most recently received items are the first to be consumed or sold. Limited physical use for perishables, but sometimes used as an accounting method for inventory valuation independent of actual physical flow.
Last-Mile Delivery
The final leg of a shipment's journey, from the last distribution point to the end customer's door. This stage is typically the most expensive and complex part of a distribution network, especially in dense urban areas or remote regions.
Lead Time
The time between placing an order (purchase or production) and that item being ready for use. Lead time can include supplier manufacturing time, transportation, customs clearance, and quality inspection, and directly drives reorder-point and safety-stock calculations.
Lot Sizing
The decision of how much quantity each purchase or production order should cover — e.g. exactly matching each period's net requirement (lot-for-lot), or batched across several periods to reduce order frequency. The lot-sizing method chosen directly affects ordering and holding costs.
Master Production Schedule (MPS)
A schedule specifying how much of each finished product should be produced and when. The MPS is the bridge between high-level demand planning and detailed MRP execution, and must be reconciled against real available capacity.
Material Requirements Planning (MRP)
A calculation method that, based on the production schedule, bill of materials, and current inventory/open orders, determines the net requirement for each material in each time period and recommends the timing and quantity of purchase or production orders to prevent line stoppages.
Mean Absolute Percentage Error (MAPE)
A common forecast-error metric expressing the average absolute difference between actual and forecasted demand as a percentage of actual demand. Lower is more accurate, but it can be misleading for items with irregular demand (Z in XYZ analysis).
Milk Run
A transportation method where a single vehicle follows a fixed route, collecting or delivering loads from multiple suppliers or customers in sequence, instead of a separate trip for each. It improves vehicle fill rate and lowers transportation cost.
Min-Max Inventory Policy
A simple inventory control policy that defines a minimum level (reorder point) and a maximum level for each item. When inventory hits the minimum, an order is placed to bring it back up to the maximum — suited to relatively stable, lower-value items.
Moving Average
A simple demand-forecasting method that uses the average of the most recent periods (e.g. the last three or six months) as the forecast for the next period. Suited to relatively stable-demand items, but loses accuracy against strong trend or seasonality.
Net Requirements
The actual quantity of a material that must be ordered or produced, after subtracting on-hand inventory and open orders from gross requirements (derived from the BOM and production schedule). Net requirement calculation is the core logic of MRP.
Network Design
The process of determining the number, location, and role of warehouses, distribution centers, and production sites in a supply chain network to achieve the right balance of cost, delivery speed, and resilience. Typically done through scenario modeling of different volume and location combinations.
Overall Equipment Effectiveness (OEE)
A composite metric for measuring machine or line performance, calculated as the product of three factors: Availability, Performance, and Quality. A score of 100% means production with zero downtime, at full speed, with zero defects.
Predictive Analytics
The use of historical data, statistics, and machine learning to forecast future events, such as customer demand, equipment failure, or supplier delays. Unlike descriptive reporting that only shows the past, predictive analytics supports proactive decision-making.
Purchase Order (PO)
A formal, binding document a buyer issues to a supplier specifying the goods/services, quantity, price, and delivery terms. Once accepted by the supplier, the PO becomes the governing contract for that transaction.
Push vs Pull System
Two different logics for driving production and inventory: in a push system, production is planned ahead based on forecast; in a pull system, production or movement only starts after an actual consumption signal (such as kanban). Most real supply chains use a hybrid push-pull boundary.
Reorder Point (ROP)
The inventory level at which a new order must be placed so replenishment arrives before existing stock runs out. ROP is typically calculated as expected demand during lead time plus safety stock.
RFQ / RFP / RFI
Three common levels of formal request to potential suppliers: RFI (Request for Information) for initial market discovery, RFQ (Request for Quotation) for a well-defined item with clear criteria, and RFP (Request for Proposal) for more complex solutions requiring multi-dimensional evaluation.
Risk Pooling
The principle that pooling inventory or capacity from multiple locations or products at a central point reduces overall demand variability (because positive and negative fluctuations across locations offset each other), requiring less safety stock than keeping them separate.
Rough-Cut Capacity Planning (RCCP)
A quick, high-level feasibility check of the master production schedule against overall available capacity, before diving into detailed MRP calculations. RCCP is typically used in the S&OP cycle to quickly confirm a plan is realistic.
Safety Stock
Extra inventory held beyond forecasted demand to buffer against demand variability or supplier lead-time delays. Safety stock levels are typically calculated based on a target service level and the standard deviation of demand and lead time.
Sales and Operations Planning (S&OP)
A monthly process for aligning sales, production, procurement, and finance plans into a single decision cycle, with senior management participation. The goal is one agreed, unified plan instead of separate — and sometimes conflicting — plans from each function.
Seasonality
A recurring, predictable pattern in demand tied to specific time periods, such as monthly or seasonal cycles — e.g. higher beverage sales in summer. Forecasting models typically compute a seasonal index per period to account for this pattern.
Single Sourcing Risk
The risk of total dependence on a single supplier for a critical item, such that any disruption at that supplier directly halts production or sales. Often deliberately accepted due to that supplier's lower cost or higher quality, but must be managed with continuous monitoring.
Stockout
A situation where inventory for an item drops to zero and a customer order or production need cannot be fulfilled at that moment. Frequent stockouts usually point to weak demand forecasting, insufficient safety stock, or unreliable suppliers.
Strategic Sourcing
A systematic approach to managing the supplier base that goes beyond one-off price negotiation, encompassing market analysis, risk assessment, supply diversification, and building long-term relationships with key suppliers.
Supplier Relationship Management (SRM)
A structured approach to managing engagement with key suppliers over time, beyond isolated purchase transactions — including ongoing performance evaluation, collaborative innovation, and shared risk management. The goal is turning the supplier relationship into a strategic asset.
Supplier Scorecard
A tool for periodically evaluating key suppliers against weighted criteria such as quality, on-time delivery, and responsiveness. Results are typically used to classify suppliers into performance tiers and inform contract renewal or volume-reduction decisions.
Supply Chain Resilience
A supply chain's ability to absorb unexpected disruptions (such as a supplier shutdown, transportation crisis, or severe demand swing) and return quickly to normal performance. Resilience typically requires a deliberate trade-off against pure cost efficiency, not a free goal.
Takt Time
The rate at which a unit must be produced to exactly match the pace of customer demand. Calculated as available production time in a period divided by demand for that period, and used as the basis for designing lean production lines.
Third-Party Logistics (3PL)
A company that provides outsourced logistics services (transportation, warehousing, distribution) on behalf of another organization. Using a 3PL can reduce fixed investment in logistics assets, but requires careful contracting and service-level monitoring.
Total Cost of Ownership (TCO)
The sum of all direct and indirect costs associated with purchasing and using a good or service over its lifetime, beyond the initial purchase price — including freight, maintenance, waste, quality risk, and opportunity cost. Procurement decisions based solely on purchase price often ignore true TCO.
Vendor Managed Inventory (VMI)
A model where the supplier takes responsibility for monitoring and deciding on the buyer's inventory levels, typically with access to the buyer's real sales or consumption data. The goal is lowering coordination cost and improving service levels for both parties.
Work in Progress (WIP)
Goods that have entered the production process but have not yet become finished products. High WIP levels typically signal a bottleneck or imbalance in the production line and lock up capital in an unsellable state.
Working Capital
The difference between an organization's current assets (inventory, receivables, cash) and current liabilities. In supply chain, a large share of working capital is typically tied up in inventory, which is why inventory optimization directly affects financial health.
XYZ Analysis
A method for classifying inventory items by demand stability and forecastability, typically using the coefficient of variation. X items have stable demand, Y items show moderate variability, and Z items have irregular or intermittent demand. Often combined with ABC into a 9-cell matrix.