semi合集-English.pdf - 第93页

SEMI E10-0304 E © SEMI 1986, 2004 7 • Unworked shifts, days • Installation, modification rebuild or upgrade • Off-line training • Shutd own/ Star t-up Non- Schedu led Time Tota l Time Operations Time Uptime • Process ex …

SEMI E10-0304

the equipment to a condition where it can perform its

intended function is included in facilities-related

downtime.

5.10 NON-SCHEDULED STATE — The time (non-

scheduled time) when the equipment is not scheduled to

be utilized in production, such as unworked shifts,

weekends, and holidays (including shutdown and start-

up).

5.10.1 If equipment is out of the production plan due to

off-line training or an installation, modification,

rebuild, or upgrade (hardware or software) that cannot

be accommodated by the regular preventive

maintenance schedule, its status is the non-scheduled

state. This includes any qualification time required to

bring the equipment to a condition where it can perform

its intended function from one of these states.

5.10.2 Any maintenance done to equipment during

these periods cannot be counted in the non-scheduled

state, since all maintenance must fall into either

scheduled or unscheduled downtime (this includes

automatic maintenance routines such as a programmed

cryo pump regeneration).

5.10.3 By the same convention, any production or

engineering work done during these periods must fall

into either productive or engineering time (this includes

an unattended operation that may shut itself off “after

hours”).

6 RAM Measurement

6.1 Reliability, availability, and maintainability are

measures of equipment performance which have been

used widely in industry for decades. This section

defines them for the semiconductor industry in a

manner that is consistent with existing industrial

standards. Along with the definitions for RAM are

given indicators by which these measures can be

quantified.

6.2 EQUIPMENT RELIABILITY — The probability

that the equipment will perform its intended function,

within stated conditions, for a specified period of time.

NOTE 4: Two different methods of measuring this are

presented, productive time (Sections 6.2.1 and 6.2.2) and

equipment cycles (Sections 6.2.3 and 6.2.4):

• Productive time only considers what happens while

making units (useful for manufacturing operation

purposes).

• Equipment cycles take into account the wear and tear

created by every machine cycle during all equipment

states (useful for equipment reliability purposes).

6.2.1 MTBF

— Mean (productive) time between

failures; the average time the equipment performed its

intended function between failures; productive time

divided by the number of failures during that time.

Only productive time is included in this calculation.

Failures that occur when an attempt is made to change

from any state to a productive state are included in this

calculation. Using MTBF

, therefore, requires that the

user not only have the capability of capturing failure

information, but also tracking and categorizing total

time accurately.

time productive during occur that failures of #

time productive

MTBF

6.2.2 E-MTBF

— Mean (productive) time between

equipment-related failures; the average time the

equipment performed its intended function between

these equipment-related failures; productive time

divided by the number of equipment-related failures

during that time. Only productive time is included in

this calculation. Equipment-related failures that occur

when an attempt is made to change from any state to a

productive state are included in this calculation. Using

E-MTBF

, therefore, requires that the user not only

have the capability of capturing failure information, but

also tracking and categorizing total time and the root

causes of failures accurately.

productive time

# of equipment-related failures that

occur during productive time

–MTB

6.2.3 MCBF — Mean cycles between failures; the

average number of equipment cycles between failures;

total equipment cycles divided by the number of

failures during those cycles. This calculation

transcends equipment states to include all cycles that

the system, or subsystem, being considered

experiences. It does not require tracking equipment

states, only equipment cycles and equipment failures.

failures of #

cycles equipment total

MCBF =

6.2.4 E-MCBF — Mean cycles between equipment-

related failures; the average number of equipment

cycles between these equipment-related failures; total

equipment cycles divided by the number of equipment-

related failures during those cycles. This calculation

transcends equipment states to include all cycles that

the system, or subsystem, being considered

experiences. It does not require tracking equipment

states, only equipment cycles and equipment-related

failures and their root causes.

total equipment cycles

# of equipment-related failures

–MCB

SEMI E10-0304

• Unworked shifts, days

•

Installation, modification

rebuild or upgrade

•

Off-line training

• Shutdown/Start-up

Non-Scheduled

Time

Total Time

Operations

Time

Uptime

•

Process experiments

• Equipment experiments

•

Software qualification

Engineering

Time

Manufacturing

Time

Productive

Time

• Regular production

• Work for 3rd party

•

Rework

• Engineering runs

Standby

Time

•

No operator

• No product

• No support tool

Downtime

•

Maintenance delay

•

Repair

•

Change of

consumables/chemicals

•

Out-of-spec input

•

Facilities related

Unscheduled

Downtime

Scheduled

Downtime

•

Maintenance delay

• Production test

• Preventive maintenance

•

Change of

consumables/chemicals

•

Setup

•

Facilities related

Figure 2

SEMI E10 Summary of Time

6.3 EQUIPMENT AVAILABILITY — The probability that the equipment will be in a condition to perform its

intended function when required.

6.3.1 Equipment Dependent Uptime — The percent of time the equipment is in a condition to perform its intended

function during the period of operations time minus the sum of all maintenance delay downtime, out-of-spec input

downtime, and facilities-related downtime. This calculation is intended to reflect equipment reliability and

maintainability based solely on equipment merit.

equipment dependent uptime (%) =

equipment uptime × 100

(oper-time – (all maint-delay DT + out-of-spec input DT + fac-rel DT))

6.3.2 Supplier Dependent Uptime — The percent of time the equipment is in a condition to perform its intended

function during the period of operations time minus the sum of user maintenance delay downtime, out-of-spec input

downtime, and facilities-related downtime. This calculation subtracts only user maintenance delay downtime from

the period, thereby taking into account supplier delays for parts and service. The intention is to provide an effective

performance measurement for use in supplier service contracts.

supplier dependent uptime (%) =

equipment uptime × 100

(oper-time – (user maint-delay DT + out-of-spec input DT + fac-rel DT))

6.3.3 Operational Uptime — The percent of time the equipment is in a condition to perform its intended function

during the period of operations time. This calculation is intended to reflect overall operational performance for a

piece of equipment.

operational uptime

(%)

equipment uptime

100

operations time

SEMI E10-0304

6.4 EQUIPMENT MAINTAINABILITY — The probability that the equipment will be retained in, or restored to, a

condition where it can perform its intended function within a specified period of time.

6.4.1 MTTR — Mean time to repair; the average time to correct a failure and return the equipment to a condition

where it can perform its intended function; the sum of all repair time (elapsed time not necessarily total man hours)

incurred during a specified time period (including equipment and process test time, but not including maintenance

delay downtime), divided by the number of failures during that period.

failuresof

timerepairtotal

MTTR

6.4.2 E-MTTR — Mean time to repair equipment-related failures; the average time to correct an equipment-related

failure and return the equipment to a condition where it can perform its intended function; the sum of all equipment-

related failure repair time (elapsed time, not necessarily total man hours) incurred during a specified time period

(including equipment and process test time, but not including maintenance delay downtime), divided by the number

of equipment-related failures during that period.

total repair time for equipment-related failures

# of equipment-related failures

–MTTR =

6.4.3 MTOL — Mean time off-line; the average time to maintain the equipment in or return the equipment to a

condition where it can perform its intended function when downtime is incurred; the sum of all downtime

(scheduled and unscheduled) during a specified time period, divided by the number of downtime events during that

period.

TOL

tota

equ

pmen

ownt

events

6.4.4 Equipment Dependent Scheduled Downtime — The percent of time the equipment is not available to perform its

intended function due to scheduled downtime events such as preventive maintenance. This time period does not

include any maintenance delay downtime caused either by supplier or user. This calculation is intended to reflect

the need for preventive maintenance based solely on equipment design.

equipment dependent scheduled downtime (%) =

equipment scheduled downtime × 100

(oper-time – (all maint-delay DT + out-of-spec input DT + fac-rel DT))

6.4.5 Supplier Dependent Scheduled Downtime — The percent of time the equipment is not available to perform its

intended function due to scheduled downtime events, such as preventive maintenance. This time period does not

include any maintenance delay downtime caused by the user. This calculation is intended to reflect the need for

preventive maintenance based solely on equipment design and supplier response to service.

supplier dependent scheduled downtime (%) =

equipment scheduled downtime × 100

(oper-time – (user maint-delay DT + out-of-spec input DT + fac-rel DT))

6.5 EQUIPMENT UTILIZATION — The percent of time the equipment is performing its intended function during a

specified time period.

6.5.1 Operational Utilization — The percent of productive time during operations time. This calculation is intended

to be used for equipment utilization comparisons between operations with different work shift configurations, since

it does not include non-scheduled time.

operational utilization

(%)

roductive time

operations time

6.5.2 Total Utilization — The percent of productive time during total time. This calculation is intended to reflect

bottom-line equipment utilization.

total utilization

(%)

roductive time

total time