RSC Topic: Planning & MRP Alignment

Connecting ERP planning signals to real execution constraints.

  • production order

    A production order is a formal instruction within a manufacturing planning or execution system to produce a defined quantity of a product or intermediate, using specified materials, resources, and work steps. It is a central transactional object in ERP and MES environments that links planning, execution, and reporting.

    Key characteristics

    In regulated and industrial manufacturing, a production order commonly includes:

    • Identified product or material: Finished good, subassembly, bulk, or intermediate material number.
    • Planned quantity: Target quantity to be produced, often with tolerances.
    • Bill of materials (BOM): List of required components, raw materials, or consumables and their planned quantities.
    • Routing or operations list: Sequence of process steps, machines, work centers, or cells where work will occur.
    • Dates and scheduling data: Requested start and finish dates, scheduled times, and sometimes priority.
    • Status information: Lifecycle states such as created, released, in process, technically complete, or closed.
    • Traceability fields: Order number, batch/lot identifiers, version numbers, and links to specifications, recipes, or work instructions.
    • Cost and settlement data: Planned vs. actual labor, machine time, and material consumption for cost tracking.

    A production order may be created manually by planners or automatically by systems such as MRP, finite schedulers, or MES order-management modules.

    Operational role

    In day-to-day operations, the production order acts as the primary container for execution and feedback:

    • On the shop floor: It is used to dispatch work, allocate operators and equipment, and record completions and scrap.
    • In MES: It may be broken down into operations, jobs, or work instructions, with detailed data captured against the order.
    • In quality systems: It links in-process controls, inspections, deviations, and batch records to a specific manufacturing campaign.
    • In ERP: It is used to update inventory, confirm material consumption, and post production costs when the order is confirmed or closed.

    Relation to ISA-95 and other models

    Within the ISA-95 context, a production order commonly aligns with the concept of a work order or production schedule element sent from business planning and logistics systems (Level 4) to manufacturing operations management (Level 3). It provides the high-level demand and constraints that lower-level control, recipe, or batch systems interpret into detailed execution.

    Common variations by system

    Different vendors and sites may use slightly different terminology:

    • ERP systems often use the term production order (or process order for process industries) as the main manufacturing order object.
    • MES and scheduling tools may refine a production order into operations, work orders, jobs, or tasks while keeping the original order as the top-level reference.
    • Batch and continuous processes may map a single production order to multiple physical batches, runs, or campaigns, or conversely may group multiple orders into a shared run.

    What a production order is not

    • It is not the same as a purchase order, which requests materials or services from suppliers.
    • It is usually not the detailed control recipe or PLC program; rather, it references or triggers these in control systems.
    • It is not a complete quality record by itself, although it is often the primary key that quality and batch records reference.

    Common confusion

    Terms such as production order, process order, work order, and manufacturing order are sometimes used interchangeably. In many plants:

    • Production order / manufacturing order refers to the ERP-level object that drives planning, costing, and inventory updates.
    • Work order or job may refer to more granular execution units dispatched to specific lines or work centers.

    When integrating MES, ERP, and control systems, it is important to clarify how each system defines and uses production order and how it maps to related objects such as batches, jobs, and equipment campaigns.

  • Work In Process (WIP)

    Work In Process (WIP) commonly refers to all partially completed products within a manufacturing or industrial process that have started production operations but are not yet finished goods. WIP includes materials, subassemblies, and units currently being processed, queued between steps, or undergoing inspection or testing.

    Scope and what WIP includes

    In regulated and industrial environments, WIP typically includes:

    • Raw materials that have been issued to a work order or batch and had at least one value-adding operation performed
    • Parts or subassemblies located at workstations, in test cells, or between routing steps
    • Batches or lots in intermediate states, such as curing, cleaning, or environmental conditioning
    • Units on hold or under review that have not yet been scrapped or reclassified

    WIP usually excludes:

    • Unissued raw materials in warehouse or stockroom
    • Completed products that are in finished goods inventory or shipping
    • Tools, fixtures, and consumables that are not part of the bill of materials for the product

    WIP in systems and operations

    In manufacturing execution systems (MES), ERP, and other production IT/OT systems, WIP is represented as open work orders, batches, or units that have not yet reached a defined completion state. Typical operational representations include:

    • Open operations or routing steps on a work order or batch record
    • Units or lots with in-process status codes (for example: running, waiting, on-hold, under inspection)
    • Quantities physically located in production areas, test labs, cleanrooms, or outside processing

    WIP levels are often monitored for planning, capacity management, and compliance with internal procedures or industry standards. In regulated environments, WIP may require documented traceability, genealogy, and evidence of each processing step, including operator, equipment, materials, and test results.

    Financial and planning perspective

    From an accounting and planning viewpoint, Work In Process is a category of inventory that has accumulated direct materials, labor, and a portion of overhead but is not yet recorded as finished goods. It is used to:

    • Calculate inventory value and cost of goods manufactured
    • Support material requirements planning (MRP) and capacity planning
    • Analyze flow, lead time, and bottlenecks on the shop floor

    Common confusion and variants

    Work In Process vs. Work In Progress: In many manufacturing and industrial contexts, these terms are used interchangeably and both abbreviated as WIP. Some accounting practices use “Work In Process” for manufacturing and “Work In Progress” more broadly for long-term projects, but the distinction is not universal.

    WIP vs. finished goods: WIP covers items still in production, while finished goods are completed products ready for sale, shipment, or distribution.

    WIP vs. raw material inventory: Raw material inventory refers to materials not yet issued or processed. Once materials are issued to a job and processing begins, they typically become WIP.

    WIP in regulated and quality-focused environments

    In regulated manufacturing, managing WIP often involves:

    • Maintaining batch records or electronic device history records for in-process units
    • Tracking hold, rework, and deviation status at the unit, lot, or batch level
    • Ensuring traceability of materials, equipment, and process parameters during all in-process stages

    Operational controls on WIP, such as limits on in-process quantity or formal release steps between stages, are sometimes used to support consistent quality and audit readiness.

  • What is the difference between a PO and a work order?

    A purchase order (PO) and a work order serve different purposes in an industrial operation, even though they sometimes reference the same parts, jobs, or vendors.

    What a purchase order (PO) does

    A PO is a commercial document issued by your company’s purchasing function, usually from ERP or a procurement system. Its main roles are:

    In practice, this connects to supplier and supply chain coordination when teams need to turn the answer into repeatable execution habits.

    • Authorize purchase of goods or services from a supplier
    • Define commercial terms (price, quantities, delivery dates, Incoterms, payment terms)
    • Support receiving, three-way match (PO, delivery, invoice), and financial control
    • Provide traceable linkage to approved suppliers and part revisions

    Typical content includes part numbers or service descriptions, quantities, unit prices, delivery location, and reference numbers (e.g., RFQ, contract, or project IDs).

    What a work order does

    A work order is an execution document, usually issued from MES, ERP, CMMS, or a maintenance system. Its main roles are:

    • Authorize and schedule work to be done (manufacturing, rework, maintenance, calibration, or service)
    • Specify routing, operations, resources, and sometimes detailed work instructions
    • Collect actuals: labor, materials consumed, equipment time, and process data
    • Support traceability for what was built or serviced, when, and by whom

    Work orders may drive:

    • Production of finished goods or components
    • Internal rework or deviation activity
    • Preventive or corrective maintenance, calibration, or qualification work
    • Field service or repair jobs

    Key differences in a regulated, brownfield environment

    • Direction of flow: POs are outward-facing, sent to external suppliers. Work orders are inward-facing, directing internal teams or contracted service providers.
    • Commercial vs technical focus: POs manage commercial commitments. Work orders manage technical execution, resource use, and traceability.
    • Systems of record: POs live primarily in ERP/procurement. Work orders may originate in ERP, MES, or maintenance systems and often need integration for accurate planning and costing.
    • Traceability role: POs help show where materials or services came from and under what terms. Work orders help show how materials were transformed, which equipment and people were involved, and which procedures and revisions were followed.

    How POs and work orders interact

    In real plants, POs and work orders are often linked, but usually not one-to-one:

    • MRP or planning generates planned orders, which become work orders for internal production or purchase requisitions that convert to POs for external buys.
    • Work orders consume material that was received under specific POs, so integration is needed to maintain correct inventory, costs, and genealogies.
    • Outside processing work may require both a work order (internal routing step) and a PO (to the outside processor). The work order tracks the process; the PO tracks the commercial transaction.

    The exact linkage depends heavily on your ERP/MES/CMMS configuration, data discipline, and how rigorously you maintain routings, BOMs, and supplier catalogs.

    Common failure modes and tradeoffs

    • Blurring roles: Using POs to describe technical work in detail, or using work orders as de facto purchasing documents, can create gaps in audit trails and confusion during investigations or cost reviews.
    • Poor integration: If work orders and POs are not synchronized across ERP, MES, and maintenance systems, you can see mismatched inventory, inaccurate standard vs actual cost, and incomplete genealogy.
    • Uncontrolled changes: Changing PO contents (quantities, revisions, or suppliers) without updating associated work orders, or vice versa, undermines traceability and can create compliance risk, especially when part revisions or process changes are involved.
    • Over-automation risk: Attempts to fully replace existing PO or work order processes with a new single system often fail in long-lifecycle, regulated operations because of validation burden, integration complexity, and downtime risk. Incremental integration and clear system-of-record definitions are usually safer.

    Practical way to think about it

    • PO: “What are we buying from whom, under what terms?”
    • Work order: “What work will we perform, using which resources and materials, and how will we record it?”

    Keeping these roles clearly separated, and integrated through your ERP/MES/maintenance stack, is critical for accurate planning, cost control, and defensible traceability in regulated environments.

  • What is the job description of order management?

    In industrial and regulated manufacturing environments, “order management” is usually a cross-functional process, not a single job title. It spans how customer demand is translated into executable, compliant work orders across commercial, planning, operations, quality, and logistics systems.

    Core responsibilities of order management

    A typical order management function is accountable for:

    In practice, this connects to supplier and supply chain coordination when teams need to turn the answer into repeatable execution habits.

    • Order capture and validation
      • Receiving sales or customer orders through ERP, portals, EDI or manual entry.
      • Checking configuration, revisions, regulatory constraints, export controls and contractual requirements.
      • Verifying pricing, lead times, MOQs and capacity assumptions with planning.
      • Ensuring required technical data and specifications are complete enough for manufacturing and quality.
    • Order promise and scheduling coordination
      • Working with planning/MRP to generate realistic available-to-promise dates based on material, capacity and qualified routes.
      • Aligning sales commitments with actual shop capability, maintenance windows and qualification limits.
      • Escalating when customer need dates conflict with constrained or regulated resources.
    • Conversion to production and purchase orders
      • Triggering or reviewing creation of production orders, work orders and purchase orders in ERP/MES according to the master data and BOMs.
      • Checking that routings, special processes and required certifications are correctly reflected before release.
      • Ensuring lot/serial tracking and traceability fields are properly defined for regulated products.
    • Change, holds and exception handling
      • Processing order changes (quantities, dates, configurations) under controlled change procedures.
      • Coordinating with engineering change, quality and regulatory when product definitions or standards change mid-order.
      • Managing order holds due to credit, quality, export control, missing data or nonconformances.
    • Status tracking and communication
      • Monitoring order status across ERP, MES, warehouse and shipping systems.
      • Providing internal and external visibility on milestones, delays, partials and split shipments.
      • Ensuring that customer-facing dates are updated when production schedules or quality issues shift.
    • Shipment, documentation and closure
      • Coordinating release-to-ship based on quality release, regulatory approvals and export licenses where applicable.
      • Ensuring required documentation (certificates, test reports, as-built records, packing lists) is linked to the order.
      • Confirming that final quantities, serials and lot genealogies are accurately recorded before financial close.
    • Data quality and continuous improvement
      • Identifying recurring order errors (wrong configs, missing data, misaligned lead times) and feeding back to master data, sales and planning.
      • Helping standardize order entry and change control to reduce rework and misbuild risk.
      • Supporting audit and customer inquiries with accurate order history and traceability.

    Where order management typically sits

    In many plants, order management responsibilities are spread across several roles and teams:

    • Customer service / order entry teams manage initial order capture and customer communication.
    • Sales operations or commercial operations coordinate demand, quotes and configuration reviews.
    • Planning / MRP groups convert orders into schedules and work orders.
    • Operations, quality and supply chain handle execution, holds, nonconformances and logistics.

    In more mature or higher risk environments, there may be a dedicated order management or sales operations function that orchestrates these handoffs and enforces consistent controls.

    Systems and integration dependencies

    The specific job description depends strongly on your system landscape and process maturity:

    • Brownfield ERP/MES stacks: In mixed or legacy environments, order management often involves manual reconciliation between ERP, MES, QMS, PLM and shipping systems, plus spreadsheet tracking to bridge integration gaps.
    • Integration quality: Where ERP and MES are well integrated, order management roles spend more time on exception handling and less on re-keying data. Poor integration drives more clerical and firefighting work.
    • Regulatory and customer requirements: Aerospace, medical device, defense and similar sectors require tighter control of revisions, export restrictions, serial tracking and documentation. Order management roles must understand these constraints well enough to avoid noncompliant orders.
    • Validation and change control: Any change in order flows, fields or system logic often requires validation and formal change control. Order management teams frequently help define requirements and test order scenarios during system changes.

    Tradeoffs and failure modes

    Common challenges and tradeoffs in order management include:

    • Speed vs control: Pushing orders through quickly without proper checks can create misbuilds, scrap and customer escapes. Overly rigid checks can hurt responsiveness for low-risk products.
    • Standardization vs flexibility: Highly standardized order flows reduce errors but may struggle with engineer-to-order or one-off customer requirements.
    • System replacement vs coexistence: Attempts to fix order management by fully replacing ERP or MES often run into qualification burden, downtime risk and integration complexity. Incremental improvements, interfaces and better master data are usually more achievable in regulated, long-lifecycle plants.
    • Ownership gaps: When no single function owns end-to-end order health, issues fall between sales, planning and operations, leading to late surprises at build or ship time.

    How to define an order management job in your plant

    If you are writing a job description, the practical steps usually include:

    • Clarify which parts of the order lifecycle this role owns vs supports (entry, promise, changes, exceptions, documentation, close).
    • List the systems they must use competently (ERP, MES, QMS, PLM, shipping, customer portals, reporting tools).
    • Specify accountability for data quality (e.g., correctness of order attributes, revision, routing, traceability fields).
    • Define interfaces with planning, production, engineering, quality, finance and customer service.
    • Include expectations around support for audits, customer inquiries and continuous improvement of order flows.

    The detailed wording should be adapted to your regulatory context, current system landscape and division of responsibilities between commercial, operations and quality teams.

  • purchase order (PO)

    A purchase order (PO) is a formal commercial document issued by a buying organization to a supplier that specifies the items, quantities, prices, and terms under which goods or services are to be provided. In industrial and manufacturing environments, the PO is the primary authorization for a supplier to deliver materials, components, tooling, services, or subcontracted operations.

    Key characteristics

    In regulated manufacturing and supply chain operations, a purchase order commonly includes:

    • Buyer and supplier identification and addresses
    • PO number and issue date
    • Line items with part numbers, descriptions, and revisions
    • Quantities, unit prices, and total value
    • Requested or required delivery dates and ship-to locations
    • Terms and conditions (payment, Incoterms, liabilities, etc.)
    • Quality and regulatory requirements (e.g., certificates, FAI/AS9102 note, special processes)
    • Reference to specifications, drawings, or work instructions

    The PO is typically created and managed in an ERP or procurement system and is often integrated with MRP, inventory, accounts payable, and supplier collaboration tools.

    Operational role in manufacturing

    Operationally, the purchase order:

    • Links demand to supply by tying MRP or planning requirements to specific external supplies
    • Provides the primary structure for tracking supplier commitments, delivery status, and backlog
    • Serves as the reference for receipts, inspections, and NCRs at incoming inspection
    • Feeds financial processes such as accruals, three-way match (PO, receipt, invoice), and costing
    • Often links to internal work orders or projects to maintain traceability of purchased content into finished goods

    In many aerospace and regulated environments, detailed line-level PO data (part, revision, lot, required certs) is used to maintain traceability and to verify that supplier deliveries meet contractual and regulatory requirements.

    PO in backlog and risk visibility

    For supply chain and capacity management, purchase orders provide the structure against which suppliers communicate confirmations, updated delivery dates, capacity constraints, and change notifications. Backlog execution risk and material shortage risk are typically assessed by comparing supplier-confirmed PO data to internal demand dates, work orders, and program schedules.

    What a purchase order is not

    • It is not an invoice. The supplier invoice is a billing document raised after shipment or service, often matched back to the PO.
    • It is not a contract in the broader legal sense, although it usually incorporates or references contractual terms.
    • It is not a work order. Internal work orders govern in-plant manufacturing steps, whereas POs govern external procurement and services.

    Common confusion

    • PO vs. purchase requisition (PR): A purchase requisition is an internal request to buy; the purchase order is the external document sent to the supplier.
    • PO vs. schedule agreement/release: Some organizations use long-term agreements with periodic releases instead of discrete POs for each order; the release still functions similarly to a PO line operationally.