TPM Route to World Class Performance Part 8 pps

The measurement cycle The condition cycle Figure 6.7 The TPM improvement plan The problem prevention cycle Mechanical actuators tooling chuck adjustment of spindle breaking re

0 Decide on the refurbishment programme

Determine the future asset care regime

Problem prevention cycle

Agree on best practice routines

Achieve improvement through problem solving and prevention For convenience, the nine-step TPM improvement plan is repeated here as Figure 6.7

The

measurement cycle

The condition cycle

Figure 6.7 The TPM improvement plan

The problem prevention cycle

Mechanical

actuators

tooling

chuck

adjustment of

spindle breaking

remote

Hydraulic

pipework

lubrication pump

Figuve 6.8 Miller M201 major components

Applying the TPM improvement plan 123

6.4 Equipment description

As a first step, some of the main components of the M201 miller are described

in Figure 6.8 and illustrated in Figure 6.9

Plan view

Figure 6.9 Miller M201 component diagram (see Figure 6.8 for key)

The performance data for the M201 are given in Table 6.1 A three-week The M201 operation cycle is shown in Figure 6.10 The operations layout equipment history is provided by Table 6.2

for Department 50 is given in Figure 6.11

Table 6.1 Miller M201 performance data

~~

Maximum spindle speed

Maximum axis feed rate

Current spindle speed

Current x and y axes feed rates

Current z axis feed rate

Time for first cut of hexagonal

Time for subsequent hexagonal cuts

Total number of subsequent cuts

Total time for all cuts

z axis travel per cut

z axis total travel

3750 rpm

1 m/min

2000 rpm 0.5 m/min

25 mm/min

33 s

15 s each

4

93 s

2 m m

10 mm

Table 6.2 Miller M201 equipment history

Cycle time 3.00 min

Week based stoppages availability stoppages Changeover Uptime Completed Rework time

no on (mini (min) (mini ( m i d (min) cycles OK

1440

rnin

15 M 530 910

W 530 910

Th 530 910

Fr 530 910

16 M 530 910

T 530 910

W 530 910

Th 530 910

F 530 910

17 M 530 910

W 530 910

Th 380 1060

120

153

96

132

129

90

42

42

99

50

27

115

34

356

46

20

20

13

9

9

20

32

12

24

5

17

790

737

814

759

769

820

859

859

79 1

860

851

783

852

700

847

124 13 111

175 13 162

151 118 33

203 51 152

236 76 160

2546

Applying the TPM improvement plan 125

Load into an open three-

to a stop

c

Press ‘GOTO’

c

1 Press green start button 1

For the first component of the day, ramp up the feed rate to allow warm-up

Programme execution:

A Move from park to site

B Make first hexagon cut

C Drop 2 mm, make second cut

D Repeat C three times

E Move to park location

1 Brushoff local swarf 1

I Place part in tray I

4

When full, pass tray to

next operation

Figure 6.10 Nlilleu M201 machine/operator cycle

Any problems

F

Call setter

i

operation

Colchester

CNC 1000

Lathe

Qp Operator primary location

Cupboards

operation

Figure 6.11 Department 50 operations layout

6.5 Equipment history recording

Newly designed record forms for cycle time and downtime are shown in Figures 6.12 and 6.13 respectively

6.6 Assessment of overall equipment

effectiveness

The OEE is given by the relation OEE = availability x performance x quality

Figure 6.12 Miller M201 equipment history record: operations

Applying the TPM improvement plan 127

Figure 6.13 Miller 201 equipment history record: downtime and faults

Example OEE calculation

The following example uses the data for the Tuesday of week 17 on the equipment history record of Table 6.2

Availability

uptime planned availability availability =

uptime = planned availability - downtime downtime = unplanned stoppages + changeovers = 115 + 12 = 127 min Therefore

uptime = 910 - 127 = 783 min availability = - 783 = 86.0%

910 Performance

completed cycles planned cycles performance =

completed cycles = 203

- - 783 - 261 planned cycles = uptime -

standard cycle time 3

Therefore

203

261 performance = - = 77.7%

Quality

(RFT = right first time)

components (RFT) completed cycles quality =

components (RFT) = 152 completed cycles = 203 Therefore

152 quality = = 74.9%

203 OEE = 86.0% x 77.7% x 74.9% = 50%

A summary of the OEE values for the equipment history provided (Table 6.2)

is given in Table 6.3 A simple graph of the OEE possibilities is shown in Figure 6.14

Cos Vben e fi t a na lysis

The cost/benefit analysis is based on the additional units that can be produced per week for each 1 per cent improvement in OEE

Table 6.3 Miller M201 OEE summary

T

W

Th

F

T

W

Th

F

T

W

Th

F

86.8 81.0 89.5 83.4 84.5 90.1 94.4 94.4 86.9 94.5*

93.5 86.0 93.6 66.0 93.1

71.0 75.3 45.7 82.6 68.3 55.2 79.6 79.6 45.9 70.1 78.6 77.7 75.3 56.6 83.6*

loo*

100

100 89.5 92.6 21.9

100

100

100

100

100

100

100 74.9

67.8

Difference between best of best and average: 24%

90.3%

100%

61.6 61.0 36.6 68.9 53.4 10.9 75.1 75.1 39.9 66.2 73.5 50.0 70.5 37.4 52.8 55.3% 79.0%

A real improvement potential of

Applying the TPM improvement plan 129

t

Implementation (months)

Figure 6.14 Miller M201 OEE comparison

Units per week for each 1% - total components (RFT)

improvement in OEE - average O/O OEE x 3 weeks

2546 - 15.43

55 x 3

-

-

Thus the benefit of increasing the average OEE up to the best of best OEE (approximately 79 - 55 = 24%) is equivalent to an extra 370 units per week

6.7 Assessment of the six losses

Following an initial visit to the machine and a 'brainstorming' session with the operator and maintainer, the problems identified for the M201 are as follows:

abnormal operation

electrical power loss

0 vibration

0 no airsupply

0 tooling performance affected

long cycle time

initial start-up procedure

excessive component loading time

slideway damage

operational safety

0 no reference d o m e n t a t i o n

These problems and issues have been allocated to the six losses in Figure 6.15 Part of the loss assessment record is shown in Table 6.4

Set-up and

changeover

Figure 6.15 Miller M201: problems identifed in the assessment of the six losses

Following the initial six losses assessment and brainstorming session, the team now has a clearer understanding of the main components of Machine

201 and a critical assessment has been completed as shown in Figure 6.16 Reference to this Figure shows that the control computer and compressor have the highest ranking, closely followed by the cutting tool, the dead plate ball screw and the auto lube kit

Other points to note are that the cutting tool (8 points out of a maximum

of 9) has the biggest potential impact on the OEE, as does the work piece chuck and the auto services kit

Where safety is a 3 and reliability a 3 on the same component, one can conclude that this may be an 'accident waiting to happen' (the cutting tool and control computer)

6.9 Condition appraisal

A completed condition appraisal form is shown as Figure 6.17

6.1 0 Refurbishment programme

A study of the refurbishment requirements indicated the following:

Tasks during machine operation 8 (20 hours)

Table 6.4 Miller M201 loss assessment record

Loss type Item Availability Performance Quality Associated problems/issues Impacts

-

surge/spike

Idling and Clogged tool

minor stops

Idling and Loose chuck

minor stops

coolant

0 Lost/corrupted program Immediate stop requires setter to reload Additionai start-up

0

New tool to be fitted 0 Purchase new tool Setter needed to restart

efficiency, hence affecting quality, not increased load on

machine, accelerated scrap parts wear

0 Operator needs to clean tool

Operator needed to affects quality, not

equipment

0

identified by operator:

scrap parts

0 Increases load on machine

= primary impact

@ = secondary impact

Compressor

Guards

Cleaning Kit

Gauging Tool

CRITICAL ASSESSMENT

M201 Bridgeport

Where S = Safety

A = Availability

P = Performance

Q = Quality

R = Reliability

M = Maintainability

E = Environment

c = c o s t

1 = No impact

2 = Some impact

3 = Significant impact

Figure 6.16 Critical assessment

Applying the TPM improvement plan 133

The costs of this programme are expected to be as follows:

e Labour costs

0 Material costs

0 Total costs

€790

€330

€1120 The major refurbishment tasks are:

0 Replace slide blanket

0 Replace spindle gasket oil seal and bearing

e Design workplace stop

0 Investigate vibration problem and cure

Apreferred spares listing for the M201 miller is shown in Figure 6.18 Schedules for checking and monitoring and for daily cleaning and inspection are shown

in Figures 6.19 and 6.20

Condition Appraisal - Top Sheet

Commissioned:

Warranty Ends;

Common

Equipment;

General Statement of Reliability

@neralh ryardedtiy the operator as a reLa6h machine 17ie four most signqicant reLa6iLty issues are:

‘E(ecm’calfailiure due to suyes/spi&s

?‘&ration pr06&m

Air suppCyfaiiures/lbw pressure

K u n n i q out of coolant (whm used

General State.ment of Maintainability

a r e is no planned maintenance for this machine f i e operator does not particeate in any maintenance

activity %cas for maintenance is severe@ hindered 6y the layout, i.e tab& and cup6oards close to the macfiine

Figure 6.17 Miller M201 condition appraisal record

Asset No:

Machine No:

Year of purchase: Appraisal by:

Location: Appraisal Date:

k

3 a C

Figure 6.17 (Contd)

Applying the TPM improvement plan 135

Condition Appraisal - Sheet 2 of 4

Figure 6.17 (Contd)

1A Electrical system susceptible to spikes

Condition Appraisal - Sheet 3 of 4

1D

1F

Asset No: %G!

Location

Description: %?+4w?e.M@4?%.M?2

System is temperamental at start-up NAN

Sub Asset Generic Group

1G

Denote condition as one of the following:

S = Satisfactory B/D = Broken Down NAN = Needs Attention Now NAL = Needs Attention Later

I

Cables and panels covered in swarf NAN

Generic

Group

~ ~~

2A

*2B Slide protection blanket tomholed

:k2D

Oil leak on spindle housing

Air supply pipe too long -trip hazard

Problem Found I Condition

NAN NAN

*2E

2E

Open hole on top surface - swarf/water

Coolant tray not secure

I NAN

2F Guard components not secure

2F Compliance with current regulations?

NAN NAN

2E I Coolant tray damaged

Figure 6.17 (Contd)

Applying the TPM improvement plan 137

Generic

Group

3A

3B

3B

3B

3 c

3 c

I Condition Appraisal - Sheet 4 of 4

Cabinetsltablehins restrict access NAN Table motion creates nip point NAN Wet floor - slip hazard (roof leak) NAN

No defined location for parts, incoming, outcoming NAN

or scrap

N o defined location for brush, hammer chuck key, spare

tools, file

NAN

6.1 2 Best practice routines

The key areas for attention and where best practice routines will need to be developed are as follows:

0 Asset caYe Cleaning; monitoring; planned maintenance

0 Correct operation Clear instructions; easy to operate; understand process

Good support Maintenance and operator work together Additional support

Lubricator

Moisture trap

I Preferred Spares Listing

5

6

Critical - W Dedicated - W Consumable - W

Lubricator

Moisture trap

5

6

I Gaitors

I Slide covers

I Coats

I Guard spares

l2 I

Manufacturers I

l2 I

Figure 6.18 Miller M201 asset care: spares listing

from accounts, production, design, purchase and planning (the key contacts)

Inspection Operator’s responsibility

Training Operator and maintenance

An operator training plan is drawn up at Figure 6.21 which will be supported

by highly visual single-point lessons

2

Q

d a

2 / 5 1 e n - z w

z u

S1 Oil reservoir/levels

I I

S 1 Air lubricator inspect top-up

I I

S1 Moisture trap drain

E l Motor temperature

X

S 1 Pipelines air/oil/coolant

I /

x

S1 Vice security alignment

I 1

I S1 Table height

S l a Warm-up cycle and emergency stop

X

SI Coolant levels

I I

E2 Vibration analysis motors

X

E2 Maintenance dept

l i surve ylinspectioris E2 Weekly clean routine oil slides and traverse gear

X

Signature

l l

Y

B

Frequency

1 = each component

2 = 2 per shift

3 = per shift

S = start of shift

E = end of shift

S

H

I

F

T

a,

2 Y

Y

2

-0

9

m

W DIS

Monday

Tuesday

NIS

DIS NIS

-

-

DIS Wednesday

NIS

DIS Thursday

Friday

NIS

DIS

NIS

-

-

DIS N/S

-

Saturday

Notify

maintenance

Figure 6.20 Miller M201 daily cleaning and inspection record

An example of a problem-solving document is shown in Figure 6.22 The main improvements identified, and their effects on availability, performance and quality, are shown in Table 6.5

6.1 4 Implementation

The proposed implementation programme is shown in Figure 6.23