A work plan describes the complete sequence of all work steps required to manufacture a product. It defines how an order moves through production and which resources are used. In the MES, the work plan is the operational foundation for order execution, OEE calculation, quality assurance and traceability.
A work plan typically contains the individual production steps and their sequence, the assigned machines or lines, target times and cycle times, references to parameters or recipes, and inspection and release checkpoints.
A routing describes the logical path of a product through manufacturing – where it runs. The work plan is the concrete, executable version of this routing with times, resources and parameters – exactly how it is produced. Both concepts build on each other: the routing provides the structure, the work plan fills it with executable content.
In the MES, the work plan controls which machine may process an order, which parameters or recipes are loaded, which inspections must be performed, when a step is considered complete and when the next process step starts. Without clean work plans, stable and reproducible production control is not possible.
In high-mix and make-to-order environments with hundreds or thousands of variants, the MES automatically selects the correct work plan based on product, variant, customer, line and regulatory requirements – without manual intervention.
Work plans embed quality into the process rather than at the end: defined inspection operations, mandatory approvals, parameter specifications and automatic deviation detection are direct components of the work plan. Errors are prevented within the process rather than discovered at final inspection – structurally reducing scrap and rework.
What is the difference between a work plan and a bill of materials? The bill of materials defines what a product requires – materials and components. The work plan defines how it is manufactured – steps, sequence, resources and parameters. Together they form the complete production specification in the MES: the BOM supplies the materials, the work plan supplies the process logic.
Can work plans be versioned? Yes – and this is essential for audit readiness and traceability. Every change to a work plan must be saved as a new revision so it is traceable which version was active for a specific batch. This is the direct intersection between work plan management and version control.
What happens if no work plan is stored for a product? Without a work plan the MES cannot control the order in a structured way – inspections are not enforced, parameters are not loaded, steps are not documented. The result is untraceable production without reliable quality records. In regulated industries this is not acceptable; in unregulated environments it creates unnecessary quality risk.