RSC Cluster: Scrap, Rework and Cost of Poor Quality Reduction

The Scrap, Rework and Cost of Poor Quality Cluster connects quality losses to financial impact and operational root causes. It reframes scrap and rework as symptoms of upstream process and training failures rather than isolated mistakes. The content walks through the full feedback loop from work instructions to nonconformance to corrective action and prevention. This cluster helps operations and finance leaders align improvement work with measurable cost reduction.

  • Quality cost

    Quality cost refers to the total cost associated with achieving, assuring, and failing to meet specified quality requirements for products, processes, or services. In manufacturing and other regulated operations, it is a structured way of categorizing how resources are spent to prevent defects, inspect and verify quality, and deal with nonconformities when they occur.

    Main categories of quality cost

    Quality cost is commonly broken into four groups:

    • Prevention costs: Costs incurred to avoid defects and nonconformances. Examples include training, process engineering, mistake-proofing (poka-yoke), preventive maintenance, document control, and quality planning activities.
    • Appraisal costs: Costs related to evaluating and inspecting products and processes to verify they meet requirements. Examples include incoming inspection, in-process checks, final inspection, testing, calibration, audits, and verification activities in MES or QMS workflows.
    • Internal failure costs: Costs that arise when defects are found before the product is delivered to the customer. Examples include scrap, rework, re-inspection, downgrading, line stoppages, MRB reviews, and updating records or travelers after a nonconformance is found.
    • External failure costs: Costs that arise when defects are found after delivery to the customer. Examples include returns, warranty work, field repairs, rework at customer sites, complaint handling, investigations, potential penalties, and disruptions to supply or production schedules.

    Operational use in manufacturing and regulated environments

    In industrial operations, quality cost is often tracked as part of broader cost of poor quality (COPQ) and continuous improvement efforts. Data may be captured across systems such as MES, ERP, QMS, and maintenance systems, then analyzed to:

    • Understand how much of total cost is tied to failures versus prevention and appraisal.
    • Identify high-impact sources of scrap, rework, and nonconformances.
    • Support decisions on investments in process controls, training, or automation.
    • Align quality performance metrics with financial reporting and operational KPIs.

    In regulated industries, documenting and categorizing quality costs can also support internal reviews, management reporting, and evidence for audits, without implying any specific compliance outcome.

    Common confusion

    • Quality cost vs cost of poor quality (COPQ): Quality cost usually includes all four categories (prevention, appraisal, internal failure, and external failure). Cost of poor quality commonly focuses on failure costs only (internal and external), or on the portion of quality cost that is considered avoidable. Usage varies by organization.
    • Quality cost vs general production cost: Quality cost is a subset of total production and operating cost, specifically related to quality activities and outcomes. It does not include unrelated expenses such as general administration or sales and marketing.
  • How can aerospace OEMs use MES data to work with suppliers on quality and waste?

    Using MES data to create a shared view of quality and waste

    Aerospace OEMs can use MES data to give suppliers a clear, traceable view of how their parts behave in real production, but only when data structures and traceability are well defined and stable. The practical starting point is to link supplier lots, certificates, and part identifiers to specific work orders, operations, and inspection results in MES. With that linkage in place, OEMs can regularly share summarized nonconformance trends, rework reasons, and scrap drivers tied back to supplier part numbers and lots. This creates an objective basis for supplier discussions instead of anecdotal complaints, but it only works if both sides understand how the MES records are generated and what they do not capture. Without that context, MES data can easily be misread, leading to disputes rather than improvement.

    Connecting supplier information into the MES data model

    To make MES data usable with suppliers, OEMs need consistent mapping between supplier identifiers and internal production data, which is often missing in brownfield environments. Basic integration points include purchase order numbers, supplier lot or batch IDs, and material serialization where applicable. These identifiers must flow from ERP or purchasing systems into MES and be captured at receiving, issue to work order, and point-of-use on the line. In many plants, legacy MES deployments were not designed with this level of supplier traceability, so retrofitting it may require configuration changes, validation effort, and operator retraining. OEMs should be explicit that any new data capture does not automatically improve quality; it simply improves the ability to pinpoint where quality issues are associated with specific suppliers, processes, or setups.

    In practice, this connects to scrap and rework reduction when teams need to turn the answer into repeatable execution habits.

    Using MES nonconformance and repair data in supplier reviews

    Nonconformance, deviation, and repair records in MES can be structured to support regular supplier performance reviews. When dispositions, defect codes, and root cause categories are consistently used, OEMs can segment defects by supplier, part family, process step, and aircraft or engine program. Summarized data—such as top defect codes per supplier or scrap cost by supplier part number—can then be shared in joint problem-solving sessions. However, code misuse, data entry shortcuts, and local work-arounds can distort the picture if they are not periodically audited. OEMs should treat MES-derived supplier scorecards as indicators that trigger deeper investigation, not as standalone evidence for contractual decisions or sanctions.

    Supporting joint root cause analysis and corrective actions

    MES data is useful for structuring joint root cause analysis with suppliers, especially when combined with engineering and quality records from PLM and QMS. Time-stamped data on operator, equipment, shifts, and process parameters can help distinguish supplier-induced issues from in-plant handling or process errors. For example, repeated defects on one supplier’s lot that only appear on a specific line or shift may point to internal process variation rather than incoming quality. Conversely, a defect pattern that appears across multiple lines, programs, and operators but aligns with a narrow set of supplier lots may justifiably focus investigation upstream. Both parties need to recognize that MES data usually does not capture every environmental or handling factor, so it should inform, not replace, structured investigations like 5-whys or fishbone analysis.

    Reducing waste and rework using MES process and performance data

    Beyond defect counts, MES often holds cycle-time, rework-time, and yield statistics that can highlight where supplier-related issues drive waste. OEMs can use MES to calculate additional touch labor, delays, and scrap associated with specific materials or components, then discuss these patterns with suppliers to target design, process, or packaging changes. Correlating MES process steps with supplier characteristics—such as coating type, dimensional tolerance range, or packaging method—can uncover where small upstream changes reduce downstream adjustments and rework. This kind of analysis is sensitive to data quality: missing timestamps, manual workarounds, and inconsistent use of rework operations can easily mask or exaggerate waste. Any improvement initiative should begin with a sanity check of MES event logs and routing structures in the affected areas.

    Data sharing, governance, and confidentiality with suppliers

    Using MES data with suppliers requires clear rules on what is shared, at what level of aggregation, and under which contractual and confidentiality frameworks. Detailed records may contain operator names, specific station IDs, or proprietary process characteristics that OEMs are not comfortable sharing directly. A practical approach is to create standardized, regularly refreshed views or reports that strip out sensitive plant-internal details while preserving quality and waste signals. Governance is also needed to ensure that MES configuration changes, routing updates, and code-set revisions are communicated so suppliers understand why metrics shift over time. Without this, an MES upgrade, new routing, or revised defect codes can look like a sudden quality deterioration, when it is mainly a data definition change.

    Coexistence with ERP, QMS, and supplier systems

    In most aerospace environments, MES is only one data source in a larger quality and supply chain ecosystem, and it rarely becomes the single source of truth for supplier relations. ERP will remain the system of record for purchase orders, receipts, and commercial terms, while QMS typically owns supplier approvals, SCARs, and formal corrective actions. MES contributes detailed operational evidence—where, when, and how nonconformances occur—but depends on integrations to tie that evidence back to suppliers. Attempting to replace ERP, QMS, or supplier portals wholesale with MES usually fails due to integration complexity, validation burden, and change-management risk. A more realistic path is to standardize a small set of MES outputs that feed into existing supplier-quality workflows and portals, with clear ownership and traceability.

    Constraints, validation, and change control in regulated aerospace

    Any change to MES data capture, integration, or reporting to better support supplier collaboration will likely trigger validation and change control in aerospace-grade environments. Altering fields, workflows, or defect codes can impact electronic records, audit trails, and existing procedures tied to approvals and certifications. OEMs need to plan these enhancements as controlled projects with clear requirements, risk assessment, and regression testing, not as ad hoc report changes. Long equipment and system lifecycles mean that partial, incremental improvements to data structure and traceability are often more practical than large-scale MES replacement. Throughout, OEMs should be explicit with suppliers that MES data supports, but does not guarantee, regulatory compliance or audit outcomes, and that interpretation of the data remains subject to documented quality procedures on both sides.

  • Yield

    Meaning in manufacturing and operations

    Yield commonly refers to the proportion of output from a process that meets defined acceptance criteria, usually expressed as a percentage of total input or total units produced. In industrial and regulated manufacturing, yield is used to describe how much material, product, or batch is successfully converted into conforming saleable product.

    Yield can be calculated at different levels, for example:

    – **Unit-based yield**: good units produced ÷ total units produced
    – **Material yield**: usable material output ÷ material input (by mass, volume, or count)
    – **Batch or lot yield**: quantity of acceptable product per batch ÷ theoretical or planned quantity

    Yield is typically tracked per operation, work center, production line, batch, or product family.

    How yield is used in operational workflows

    In manufacturing systems and daily operations, yield is often:

    – Captured in MES, LIMS, or batch systems at each process step
    – Calculated automatically from scrap, rework, and good output counts
    – Reported per shift, batch, order, or time period for performance monitoring
    – Analyzed by engineering, quality, and operations to identify process losses and variation

    In integrated OT/IT environments, yield may be derived from shop-floor data sources such as PLC counters, weigh scales, vision inspection results, or manual inspection records, and then consolidated in MES, data historians, or BI/operations intelligence tools.

    Common yield variants and metrics

    Several specific yield-related metrics are used in industrial contexts:

    – **First pass yield (FPY)**: proportion of units that meet specification the first time through a process, without rework
    – **Rolled throughput yield (RTY)**: probability that a unit will pass through a multi-step process without any defect, calculated by multiplying the yields of the individual steps
    – **Final yield**: proportion of units or quantity that is ultimately released as conforming product after rework and inspection
    – **Theoretical vs. actual yield**: theoretical yield is the expected or designed output based on formulas or BOMs; actual yield is the measured, realized output

    When not explicitly qualified, “yield” in many plants refers either to FPY or final yield, so it is common practice to clarify which definition is being used in reports and discussions.

    Boundaries and what yield is not

    To avoid confusion:

    – Yield **describes output quality and quantity effectiveness**, not production rate or speed. Metrics such as throughput, cycle time, and OEE address those aspects.
    – Yield **does not, by itself, indicate compliance or certification status**. It only reflects measured conformance to defined internal or external criteria.
    – Yield usually **excludes planned losses** such as scheduled maintenance or planned overfill; those are handled separately in capacity and loss accounting models.

    Yield is closely related to, but distinct from:

    – **Scrap rate**: proportion of units or material that must be discarded and cannot be used
    – **Rework rate**: share of output that requires additional processing to meet specification

    Use in regulated and quality-managed environments

    In regulated or quality-critical manufacturing (for example pharmaceuticals, medical devices, food, or aerospace), yield is typically:

    – Recorded per lot or batch, often with reference to master recipes or specifications
    – Included in batch records, device history records, or electronic production records
    – Trended in quality management and operations reviews to detect process drift or issues
    – Linked with nonconformance, deviation, and CAPA processes when unusual yield changes occur

    Systems such as MES, QMS, and ERP may share yield data to support production planning, cost accounting, and regulatory documentation.

    Common confusion and misuse

    Yield is sometimes used inconsistently across sites or departments. Typical sources of confusion include:

    – **Different bases for calculation**: some teams divide by total started units, others by total completed units. Clear definitions and documented formulas are necessary.
    – **Including or excluding rework**: some definitions count reworked units as good in the final yield; FPY explicitly excludes rework.
    – **Mass vs. count**: in bulk or process industries, yield may be tracked in mass or volume; in discrete manufacturing, it is often unit-based.

    Clarifying which yield definition, units, and counting rules are being used is essential when comparing performance across lines, sites, or reports.

    Relation to lean and continuous improvement

    In lean manufacturing and continuous improvement contexts, yield is one of the core measures used to:

    – Quantify process defects and waste (especially scrap and rework)
    – Support root cause analysis and problem-solving methods
    – Evaluate the impact of process changes, error-proofing, or standardization

    While yield alone does not prescribe any method, it is a key input into many structured improvement and problem-solving activities.

  • material yield

    Core meaning

    Material yield commonly refers to the proportion of input material that exits a process as conforming, saleable product rather than scrap, rework, or other losses. It is typically expressed as a percentage, ratio, or cost-based metric.

    In manufacturing and industrial operations, material yield is used to understand how efficiently raw and intermediate materials are converted into finished goods, considering process losses, quality defects, and handling losses.

    Typical calculation approaches

    Material yield can be calculated in several ways, depending on data availability and how the site defines waste:

    – **Quantity-based yield**
    – (text{Material Yield (qty)} = frac{text{Good output quantity}}{text{Input material quantity}})
    – Often used at line, work center, or batch level.

    – **Mass or volume-based yield**
    – Uses mass (kg, lb) or volume (L, m³) instead of unit counts.
    – Common in process industries where formulation and losses by weight/volume matter.

    – **Cost-based yield**
    – (text{Material Yield (cost)} = frac{text{Material cost in conforming output}}{text{Total material cost consumed}})
    – Links yield directly to material waste cost and is frequently used in KPI dashboards.

    Sites may include or exclude rework, by-products, or recoverable material depending on accounting rules and regulatory constraints. For this reason, material yield definitions are often documented explicitly in procedures or KPI definitions.

    Use in industrial and regulated workflows

    In regulated and complex manufacturing environments, material yield is:

    – **Tracked at multiple levels**: by part or SKU, work order, batch/lot, process step, line, and plant.
    – **Linked to quality data**: good vs. nonconforming units, scrap reasons, and rework routes from QMS or LIMS.
    – **Integrated across systems**: input quantities and costs from ERP or inventory, process quantities from MES/SCADA, and disposition information from QMS or serialization systems.
    – **Time-bounded**: reported per shift, day, campaign, or batch to support investigations and continuous improvement.

    Material yield is often included in KPI sets alongside scrap rate, rework rate, and overall equipment effectiveness (OEE) to provide a view of material efficiency.

    Boundaries and what it is not

    – **Includes**:
    – Conforming output compared to all material consumed for that output (including start-up, changeover, and in-process losses when so defined).
    – Losses due to scrap, overfill, spillage, evaporation or reaction losses (when material balance is modeled), and non-recoverable rework.

    – **Common exclusions (when defined separately)**:
    – Energy efficiency, labor productivity, or equipment utilization (these are distinct performance dimensions).
    – Pure yield-loss causes that are treated as separate KPIs (e.g., overfill, giveaway, or packaging damage), unless the local definition consolidates them.

    Because definitions vary, material yield figures from different plants or systems are not always directly comparable without understanding the underlying rules and data sources.

    Common confusion and related terms

    – **Yield vs. scrap rate**:
    – Material yield focuses on the proportion of material that becomes conforming product.
    – Scrap rate focuses on the proportion of material or units that are discarded.
    – They are mathematically related but framed from different perspectives.

    – **Yield vs. first pass yield (FPY)**:
    – FPY measures how many units pass a process without rework.
    – Material yield can count material that eventually becomes conforming product after rework, depending on the site definition.

    – **Yield vs. recovery**:
    – In some process industries, **recovery** is used for how much desired substance is obtained from a raw feed.
    – Material yield may be a broader metric across the full manufacturing chain, not just a single separation or reaction step.

    When reporting or comparing metrics, it is common practice to specify whether rework, by-products, and recoverable material are included in the yield calculation.

    Site-context application: material waste KPIs

    In the context of KPIs for material waste reduction:

    – Material yield is used as a **rate-based KPI** that complements scrap and rework rates.
    – Plants often derive both **quantity-based** and **cost-based** material yield, so that yield losses can be tied to actual material cost and regulatory constraints (e.g., restricted or serialized lots).
    – MES, ERP, and QMS integration enables tracking of material yield by part, routing step, and batch, supporting root-cause analysis when yield losses occur.

    In regulated environments, consistent and clearly documented definitions of material yield are important so that reported KPIs remain traceable, reproducible, and suitable for audit or review.