Production Planning and Production Scheduling ConceptsDEFINITIONS
Let us first look at some definitions from APICS (American Production and Inventory Control Society) Dictionary.
Production Planning A process to develop tactical plans based on setting the overall level of manufacturing output (production plan) and other activities to best satisfy the current planned levels of sales (sales plan or forecasts), while meeting general business objectives of profitability, productivity, competitive customer lead times, and so on, as expressed in the overall business plan. The sales and production capabilities are compared, and a business strategy that includes a sales plan, a production plan, budgets, pro forma financial statements, and supporting plans for materials and workforce requirements, and so on, is developed.
One of its primary purposes is to establish production rates that will achieve management’s objective of satisfying customer demand by maintaining, raising, or lowering inventories or backlogs, while usually attempting to keep the workforce relatively stable. Because this plan affects many company functions, it is normally prepared with information from marketing and coordinated with the functions of manufacturing, sales, engineering, finance, materials, and so on.
Production Scheduling The process of developing the production schedule – A plan that authorizes the factory to manufacture a certain quantity of a specific item. It is usually initiated by the production planning department.
Capacity Planning The process of determining the amount of capacity required to produce in the future. This process may be performed at an aggregate or product-line level (resource requirements planning), at the master-scheduling level (rough-cut capacity planning), and at the material requirements planning level (capacity requirements planning).
Infinite Loading or Infinite Scheduling Calculation of the capacity required at work centres in the time periods required regardless of the capacity available to perform this work.
Finite Loading or Finite Scheduling Assigning no more work to a work centre than the work centre can be expected to execute in a given time period. The specific term usually refers to a computer technique that involves calculating shop priority revisions in order to level load operation by operation.
Drum-Buffer-Rope (DBR) The theory of constraints method for scheduling and managing operations that have an internal constraint or capacity-constrained resource.
Forward Scheduling A scheduling technique where the scheduler proceeds from a known start date and computes the completion date for an order, usually proceeding from the first operation to the last. Dates generated by this technique are generally the earliest start dates for operations.
Backward Scheduling A technique for calculating operation start dates and due dates. The schedule is computed starting with the due date for the order and working backward to determine the required start date and/or due dates for each operation.Advanced Planning and Scheduling (APS) Techniques that deal with analysis and planning of logistics and manufacturing during short, intermediate and long-term time periods. APS describes any computer program that uses advanced mathematical algorithms or logic to perform optimization or simulation on finite capacity scheduling, sourcing, capital planning, resource planning, forecasting, demand management, and others. These techniques simultaneously consider a range of constraints and business rules to provide real-time planning and scheduling, decision support, available-to-promise, and capable-to-promise capabilities. APS often generates and evaluates multiple scenarios. Management then selects one scenario to use as the official plan. The five main components of APS systems are
- Demand Planning
- Production Planning
- Production Scheduling
- Distribution Planning
- Transportation Planning