MES and production glossary.

OEE

Overall Equipment Effectiveness · FR: TRS

Overall Equipment Effectiveness is the share of planned production time that produced good parts at full speed. It is the product of three factors, availability, performance and quality, each a ratio between zero and one.

The figure means nothing without the period it covers and the stops it counts. Two plants quoting the same OEE can be excluding different planned time, using different reference cycle times and counting rework differently. The OEE calculation guide works through each factor and the inputs behind it.

Availability

Availability rate · FR: disponibilité

Availability is the time a machine actually ran as a share of the time it was required to run. It is the first OEE factor and carries every loss that stops the machine: breakdowns, changeovers, waiting for material, waiting for an operator.

The argument is always about the denominator. A plant that removes planned maintenance, breaks and unmanned shifts from required time reports a higher figure than one that does not, and neither is wrong as long as the choice is stated. Short stops below a recording threshold are the usual reason availability looks better than output suggests.

Performance

Performance rate, speed rate · FR: performance

Performance is what a machine produced while running, as a share of what it would have produced at its ideal rate in the same time. It is the second OEE factor and carries speed losses and stops too short to have been recorded.

Its reference is the ideal cycle time, and that is where the figure is usually bent: a rate lowered to match what the line actually achieves makes performance look healthy and hides the loss. A good availability figure beside a poor performance figure most often means short stops are going unrecorded rather than that the machine is slow.

Quality rate

Quality factor · FR: taux de qualité

The quality rate is the number of good units as a share of all units produced. It is the third OEE factor and carries every unit that was scrapped or had to be reworked.

The definitional question is what counts as good. Some plants count a reworked unit as good, others count it as a reject, and a part rejected at final inspection may or may not be charged back to the machine that made it. Each choice is defensible; what matters is that it is made once and applied everywhere.

AFNOR NF E60-182

French standard for production rates

AFNOR NF E60-182 is the French standard that defines the time categories of a production resource and the rates computed from them, including the TRS, the French equivalent of OEE. It sets out total time, opening time, required time, operating time, net time and useful time, and the losses between each.

Its value is that it names the categories, so two sites working to it can compare figures without first comparing spreadsheets. It also defines the TRG and the TRE, which divide by opening time and total time rather than by required time. VZIAM MES computes its rates to this standard.

TEEP

Total Effective Equipment Performance

TEEP measures good output against all calendar time, not just planned production time. It is OEE multiplied by utilisation, the share of calendar time that was scheduled for production.

OEE answers how well the planned time was used; TEEP answers how much of the week the equipment was used at all. A line with a high OEE on one shift a day has a low TEEP, which is the figure that matters when the question is whether to buy another machine or run the existing one longer.

Ideal cycle time

Nominal rate, theoretical cycle time · FR: temps de cycle de référence

The ideal cycle time is the shortest time in which a machine can produce one unit of a given product under good conditions. Its inverse is the nominal rate, and it is the reference the performance factor is measured against.

It belongs to a product on a machine, not to the machine alone: the same press runs different parts at different rates. Taking it from the equipment nameplate, from a validated trial or from the best rate actually recorded gives three different figures, and the source should be written down beside it.

Micro-stop

Short stop, minor stop · FR: micro-arrêt

A micro-stop is a stop short enough that it is cleared on the spot and rarely recorded by hand: a jam, a misfeed, a sensor that needs a reset. Most definitions set a duration threshold below which a stop counts as micro.

Individually trivial and collectively large, micro-stops usually appear only as a gap between expected and actual output. Under AFNOR NF E60-182 they are a performance loss rather than an availability one, which is why they are kept out of failure counts such as MTBF.

Stop reason

Downtime reason, stop cause · FR: cause d’arrêt

A stop reason is the cause recorded against a period when a machine was not producing, chosen from a list the plant maintains. It is what turns a duration into something that can be ranked, assigned and worked on.

The list decides the analysis. Too short and everything lands in a catch-all; too long and operators pick the first plausible entry. Most plants settle on a tree of a few top-level families with more detail underneath, and keep the difference between a machine’s own stop and one induced by its neighbours.

Changeover

Setup, format change · FR: changement de série

A changeover is the time between the last good unit of one product and the first good unit of the next on the same equipment. It includes the mechanical setup and the adjustment runs until output is good again.

SMED, single-minute exchange of die, is the method for shortening it: separate what can be done while the machine still runs from what cannot, then move as much as possible into the first group. Whether changeover counts against availability or is planned out of required time is a choice that changes the OEE figure considerably.

Bottleneck

Constraint · FR: goulot d’étranglement

The bottleneck is the resource whose capacity limits the output of the whole line. An hour lost there is an hour lost for the line; an hour lost elsewhere may be absorbed by a buffer.

It is rarely the machine that stops most, because on a coupled line many recorded stops are consequences of a stop somewhere else. Finding it means telling a machine that stopped from one that was starved or blocked, which the guide on identifying bottlenecks sets out step by step.

Takt time

Customer demand rate

Takt time is the available production time divided by the customer demand over the same period. It is the pace at which one unit must be finished to meet demand, set by the customer rather than by the equipment.

Comparing it with the cycle time of each step shows where a line cannot keep up: a step slower than takt is a constraint, and one much faster is spare capacity. It is a planning figure, so it changes when demand or shift patterns change, and a line balanced to an old takt is balanced to the wrong number.

MES

Manufacturing Execution System

A Manufacturing Execution System records and directs what happens on the production floor: which order runs on which machine, what the machine did, what was produced and what went wrong. It sits between the controllers on the machines and the ERP that plans and costs the business.

The useful boundary is the grain of the record. An MES holds every state change, stop and declaration; an ERP holds one posting per order or shift. ISA-95 calls this level 3, manufacturing operations management, and the MES vs ERP comparison sets out where each one stops.

ISA-95

IEC 62264

ISA-95 is the international standard for integrating enterprise systems with manufacturing control systems. It defines the levels of a plant, from the physical process at level 0 to business planning at level 4, and the information exchanged between levels 3 and 4.

Its most used part is the vocabulary: work orders, material definitions, equipment hierarchies and production responses mean the same thing to both sides of an ERP integration. It describes interfaces and models, not software, so two products can both follow it and still need mapping to talk to each other.

Work order

Production order, manufacturing order · FR: ordre de fabrication (OF)

A work order is the instruction to make a stated quantity of one product, by a stated date, following a given routing. It is usually created in the ERP and executed and recorded in the MES.

It is the unit everything else attaches to: the time a machine spent, the material it consumed, the stops it suffered and the quality checks it passed. When one order is one finished lot, the order’s record is also the lot’s, which is what makes traceability straightforward to query.

Routing

Process plan, operations list · FR: gamme

A routing is the ordered list of operations a product goes through, with the resource each one uses and the time it is expected to take. With the bill of materials, it defines how a product is made.

The planned times in a routing feed costing and scheduling, so they tend to drift away from what the floor actually achieves. An MES that copies the routing onto the order when it starts keeps a record of what was planned at the time, which stays true even after the master routing is edited.

Bill of materials

BOM · FR: nomenclature

A bill of materials lists the components, raw materials and quantities needed to make one unit of a product, often as a tree of sub-assemblies. It defines what a product is made of.

An engineering BOM describes the design and a manufacturing BOM describes how the plant actually builds it, and the two often differ. On the floor, the BOM is what a material consumption is checked against and what links a finished lot to the component lots in its genealogy.

Work in progress

WIP · FR: en-cours

Work in progress is material that has entered production and not yet been finished: parts between operations, in buffers or waiting for a resource. It is value tied up on the floor.

Some WIP protects the bottleneck from stops upstream, and too much hides problems and lengthens lead time. Where it accumulates is informative: a growing queue in front of one machine points at the constraint more reliably than that machine’s own stop history.

Shift report

Shift handover · FR: rapport de poste

A shift report summarises what a production team made during its shift, what stopped, what was rejected and what the next team needs to know. It is the main channel between shifts.

On paper it is written at the end of the shift from memory, so durations are rounded and short stops left out. Produced from recorded data it starts complete, and the team’s time goes into the part only a person can add: what they saw and what they suspect.

Scrap and rework

Rejects · FR: rebut et retouche

Scrap is output that cannot be used and is discarded or recycled. Rework is output that fails a requirement and is corrected to meet it, at the cost of extra time and handling.

Both are quality losses, but they are counted differently from plant to plant: rework is sometimes treated as good output and sometimes as a reject, and start-up scrap after a changeover is sometimes excluded. A reject declared against a reason at the moment it happens is what makes a scrap Pareto agree with the quality rate.

First pass yield

FPY, right first time · FR: rendement premier passage

First pass yield is the share of units that pass through a process correctly the first time, without rework or repair. Units that are reworked and then pass do not count towards it.

It is stricter than the quality rate when rework counts as good, and the gap between the two measures the hidden factory: the effort spent correcting work. Rolled throughput yield multiplies the first pass yields of each step to give the chance a unit passes the whole line untouched.

Genealogy

Product genealogy, lot genealogy · FR: généalogie

Genealogy is the record linking a produced lot to the lots of material and components that went into it, the equipment that made it and the period it ran in. It is the data structure traceability is read from.

It has to be recorded at the time, because it cannot be reconstructed reliably afterwards: which reel was on the machine when a lot started is known for certain only then. Each link is a consumption, so a genealogy is only as complete as the consumptions that were declared.

Traceability

FR: traçabilité

Traceability is the ability to follow a product through its history in both directions: forward from a suspect material to every lot it went into, and backward from a finished unit to everything that made it.

Its test is a recall. The question is how quickly and how narrowly a plant can say which lots are affected, and the narrower the answer, the less has to be recalled. Regulated sectors such as food, automotive and pharmaceuticals set requirements on what must be kept and for how long.

Batch record

Electronic batch record, EBR · FR: dossier de lot

A batch record is the documented history of one batch or lot: the instructions followed, the materials used, the checks made, the deviations and who signed for each step. It is the evidence that the batch was made as specified.

On paper it is assembled after the event and reviewed by hand before release. Recorded electronically as the batch runs, it is complete when the batch ends, and the review can concentrate on the exceptions rather than on checking that every box was filled.

Andon

FR: andon

Andon is a visual signal that shows the state of a line and calls for help when something goes wrong: originally a cord or a light, now often a screen on the shop floor. The word comes from the Toyota Production System.

Its purpose is a fast response, not a display. An andon that lights up and draws nobody is decoration, so the signal has to name what is wrong and reach the person who can act. Large screens showing each line’s state and open alerts are the common modern form.