Planning and Scheduling

In the Supply Chain domain, planning and scheduling are key steps to effectively steer production, optimize resources and meet customers’ expectations in terms of lead time and quality. Good planning consists of anticipating demand, allocating production capacities and synchronizing the different flows (raw materials, semi-finished, finished products), while scheduling aims to concretely organize tasks and production sequences at the operational level.

In this article, we will define these concepts, explain their complementarity and present the methods and tools that help reduce costs, improve responsiveness and maximize customer satisfaction.

What is planning and scheduling?

Planning

Medium- to long-term view (monthly, quarterly, annual horizon), integrating sales forecasts, production capacities and inventory levels.
Aims at defining master plans (Master Production Schedule), an overall plan of needs in materials, labor and equipment to meet demand.

Scheduling

Short-term and operational view, organizing the priority and sequence of tasks on production lines, machines or workstations.
Seeks to optimize sequencing (minimize changeover times, lead times, costs, etc.) and to respect constraints (resource availability, maintenance, delivery deadlines).

Why are they complementary?

Planning sets out the main lines of production (what to produce, in what quantity, when to start the batches) by taking into account sales forecasts and inventories.
Scheduling refines and translates these orientations into a precise timetable (which operator, which machine, at what time), in order to reduce waste and idle time.

The stakes of planning and scheduling

Meeting deadlines and customer satisfaction

Deliver on time, avoid delays and penalties, maintain a high service rate.

Resource optimization

Avoid overloads or underuse of production lines, balance the workload.
Reduce costs (labor, machines) and improve productivity.

Reduction of inventory and work-in-progress

Sequence operations to avoid accumulating unnecessary work-in-progress.
Limit storage costs and capital immobilization.

Responsiveness and flexibility

Quickly adapt the production plan in case of demand fluctuations, breakdowns, supplier delays.
Set up alternative scenarios to handle hazards.

Cross-functional collaboration

Coordinate procurement, production, logistics, sales and finance to share information (forecasts, capacities) and align priorities.

The main planning methods

S&OP (Sales and Operations Planning)

Monthly or quarterly consultation process between sales, marketing, production and finance teams.
Leads to a global plan (Production, Distribution, Procurement) aligned with commercial and financial objectives.

MPS (Master Production Schedule)

Detailed production program derived from sales forecasts and target inventories.
Translates objectives into production volumes per period and per product family.

MRP (Material Requirements Planning)

Calculates net needs in components and raw materials, based on:
- The MPS,
- The product bills of materials (BOM),
- Existing inventories,
- Supplier lead times.
Issues purchase or manufacturing orders to satisfy demand.

DRP (Distribution Requirements Planning)

Extends the MRP logic to distribution (multi-warehouse, multi-level).
Determines how to allocate finished stocks across the different logistics platforms or subsidiaries.

APS (Advanced Planning & Scheduling)

Advanced optimization and planning systems (often integrated with the ERP).
Allow processing of large amounts of data, simulating different scenarios and solving complex problems (machine, labor, transport constraints).

Scheduling: principles and algorithms

Priority rules

FIFO (First In, First Out): tasks are processed in the order of arrival.
EDD (Earliest Due Date): priority to tasks with the closest due date.
SPT (Shortest Processing Time): priority to the shortest tasks.
These rules are simple to apply but do not always guarantee a global optimum.

Scheduling algorithms

Gantt: visual representation of tasks and their sequence on a diagram.
Flow shop: scheduling of flows (sequence of machines).
Job shop: varied tasks going through different machines with specific paths (more complex).
Heuristics or meta-heuristics (Branch & Bound, Tabu Search, Genetic Algorithms): used to solve complex large-scale scheduling problems.

Multiple constraints and objectives

Minimize makespan (total processing time), the number of late jobs, waiting time, work-in-progress.
Take into account optimal sequencing to avoid setup times, limit scrap, respect maintenance constraints.

Discover the Platform

Tools and IT solutions

ERP (Enterprise Resource Planning)

Offers planning modules (MPS, MRP) and generates production orders.

APS (Advanced Planning System)

Specialized solutions (Quintiq, Kinaxis, OMP, etc.) offering advanced multi-constraint planning and scheduling algorithms.
Enable simulations, schedule optimization and what-if-analysis scenarios.

Scheduling software

Dedicated to a type of environment (flow shop, job shop, mixed).
Provide interactive Gantt charts, configurable heuristics and real-time monitoring (MES, Manufacturing Execution System).

MES (Manufacturing Execution System)

Shop-floor steering interface, ensuring the link between the ERP (production order) and machines/operators.
Collects production data (time spent, quantities produced, stops) and updates progress.

Best practices for high-performance planning and scheduling

Master data quality
- Make sales forecasts, bills of materials, process times and supplier lead times reliable.
- Regularly update performance indicators (scrap rate, actual pace).
Choose the right granularity
- Adjust the planning horizon (monthly or quarterly S&OP, weekly MPS, daily or real-time scheduling).
- Avoid overloading the scheduling system with too much precision, unless necessary (responsiveness, make-to-order).
Collaborate closely with other functions
- Align production plans and procurement (see Inventory and Flow Management).
- Exchange real-time information with logistics, maintenance and the sales department.
Involve operational teams
- Operators, shop foremen and production managers must understand the planning and scheduling logic.
- Collect their feedback to improve the rules and on-site feasibility.
Set up monitoring and continuous improvement
- Define KPIs (schedule adherence rate, service rate, machine utilization rate).
- Analyze deviations and root causes (breakdowns, absences, forecast errors).
- Adjust parameters (lot size, setup time) and explore new heuristics if needed.
Manage hazards and flexibility
- Plan safety margins (buffer stock, reserve time) to handle emergencies or incidents.
- Set up fallback scenarios (quick replanning, staff versatility, redeployment to other lines).

In summary

Planning and scheduling are two pillars of Supply Chain management, allowing to synchronize production, inventory and demand:

Planning defines a strategic and tactical framework (S&OP, MPS, MRP) to ensure alignment between forecasted demand and available resources.
Scheduling operates at the operational level, organizing tasks and their sequence to minimize waiting times, work-in-progress and costs.

For Procurement and Supply Chain professionals and students, it is essential to:

Understand the methods (S&OP, MRP, APS, scheduling algorithms) and their limitations.
Select the tools (ERP, APS, MES) suited to the company’s needs (complexity, volumes, demand variability).
Foster collaboration between departments (sales, production, logistics, finance) and cross-functional information sharing.
Master the indicators (service rate, machine utilization, OTIF, cycle time) to continuously refine planning and scheduling.
Adopt a continuous-improvement culture that integrates responsiveness to hazards, line flexibility and data quality.

By combining robust planning with fine and responsive scheduling, the company can maximize customer satisfaction (lead times, quality) while controlling its production and storage costs.