Time Bucket
Definition
A time bucket is the unit of time — typically a day, week, or month — into which a planning system groups demand, supply, and schedule data, defining the granularity of an MRP or forecasting plan.
In Practice
Bucket size sets how precisely a plan can time events: weekly buckets are the classic MRP standard, giving enough resolution to schedule order releases without drowning planners in detail, while monthly buckets suit long-horizon S&OP and daily buckets suit near-term execution. Many systems use telescoping buckets — daily for the next two weeks, weekly out to three months, monthly beyond.
Modern bucketless systems store every requirement by exact date and let the user choose display buckets, but the concept still governs how plans are reviewed and how demand is aggregated for forecasting.
Frequently Asked Questions
What time bucket size should MRP use?
Weekly buckets are the common default: fine enough to schedule releases and spot exceptions, coarse enough to stay manageable. Use daily buckets inside the execution horizon where sequencing matters, and monthly buckets for long-range planning. Buckets larger than a month can hide timing problems inside the bucket.
What is a bucketless system?
A bucketless MRP system stores requirements and receipts by exact need date rather than accumulating them into fixed periods. Planners then view the data through whatever display buckets they choose. It gives more precise scheduling while keeping reports readable at any level of aggregation.
Related Terms
Back scheduling (backward scheduling) is a planning method that starts from a job's required due date and works backward through each operation's lead time to find the latest possible start date for every step.
Material Requirements Planning (MRP)Material Requirements Planning (MRP) is a calculation engine that translates a production schedule into time-phased requirements for every component and raw material, using bills of materials, inventory records, and lead times.
Master Production Schedule (MPS)The Master Production Schedule (MPS) is the anticipated build plan for finished products or key end items, stating what will be produced, in what quantity, and in which time period. It is the primary input that drives MRP.
Pyramid ForecastingPyramid forecasting is a technique that reconciles forecasts made at different levels of aggregation — item, product family, and total business — so that detailed and summary plans always roll up and force down to consistent numbers.