A sustainability approach for selecting maintenance strategy

Figures & data

Table 1 Business sustainability subcriteria.

Pillar	Subcriteria
Business excellence/economic factors	1. Hardware cost	17. Mean time to repair
	2. Applied technology complexity	18. Manufacturing system type
	3. Software cost	19. Detailed production scheduling
	4. Mean time between failures	20. System design
	5. Risk level of the system	21. Repairability
	6. Research and development cost	22. Failures type severity
	7. Customer satisfaction	23. Technical feasibility
	8. Product variety	24. Flexibility
	9. Creativity	25. Return on investment
	10. Product development stage	26. Demand urgency
	11. Competitive enhancement	27. Spare machine availability
	12. Current reliability level	28. Spare parts availability
	13. Reliability improvement plans	29. Tear and wear rate
	14. Access difficulty	30. Lead time
	15. Quality of the product/service	31. Lost production cost
	16. Time efficiency	32. Personnel training cost

Table 2 Social sustainability subcriteria.

Pillar	Subcriteria
Social/human contribution factors	1. Stakeholder participation	6. Development of management and engineering expertise
	2. Employment issues	7. Personnel health
	3. Personnel safety	8. Personnel wage
	4. Personnel training	9. Government regulations
	5. Acceptance by personnel	10. Holding related to social standards

Table 3 Environmental sustainability subcriteria.

Pillar	Subcriteria
Environmental factors	1. Energy consumption	6. Waste cleaning cost
	2. Holding environmental standards	7. Waste type
	3. Environmental planning	8. Toxic emissions to air, soil and water
	4. Inside toxic emissions	9. Resource availability
	5. Raw material consumption	10. Environmental management systems

Figure 1 FA (p < t).

Table 4 Fuzzy linguistic terms in assessing the impact of each subcriterion on each sustainability pillar.

Linguistic term	Fuzzy triangular number
Very low (VL)	(0, 0, 0.1)
Low (L)	(0, 0.1, 0.3)
Medium low (ML)	(0.1, 0.3, 0.5)
Medium (M)	(0.3, 0.5, 0.7)
Medium high (MH)	(0.5, 0.7, 0.9)
High (H)	(0.7, 0.9, 1)
Very high (VH)	(0.9, 1, 1)

Table 5 Business and economic FA results after rotation.

	Factor 1	Factor 2	Factor 3	Factor 4	Factor 5	Factor 6
Z1	− 18	4	91*	4	10	12
Z2	− 48*	− 4	38	13	17	− 14
Z3	− 5	− 9	65*	− 8	14	8
Z4	17	4	12	− 4	86*	9
Z5	12	35	41	− 9	0	61*
Z6	30	76*	0	− 9	2	− 32
Z8	− 13	72*	− 13	16	6	− 6
Z9	26	88*	5	− 8	− 8	− 4
Z10	8	85*	6	19	2	16
Z11	− 1	91*	− 13	9	6	1
Z14	60*	40	4	− 42	− 14	5
Z15	− 23	32	− 21	63*	14	4
Z16	33	40	− 2	31	69*	5
Z17	1	7	10	15	77*	7
Z18	− 9	− 9	24	28	17	77*
Z20	38	− 25	34	− 40	14	47*
Z21	67*	33	25	17	7	25
Z22	74*	2	13	− 16	21	2
Z23	58*	− 11	27	− 45	− 2	17
Z24	67*	19	− 17	− 6	− 30	23
Z26	9	3	34	65*	− 17	10
Z27	89*	10	3	18	9	− 16
Z28	82*	2	− 3	10	4	− 22
Z29	58*	20	2	21	25	− 13
Z30	2	4	− 27	80*	21	15
Z31	30	35	47*	− 11	1	− 7
Z32	33	− 5	71*	− 14	− 1	13

Table 6 Secondary social FA results after rotation.

	Factor 1	Factor 2	Factor 3
X1	56*	− 11	16
X3	9	81*	1
X4	− 19	13	80*
X5	33	− 38	55*
X6	73*	17	− 11
X7	0	74*	24
X8	31	27	56*
X9	84*	− 4	22
X10	54*	4	− 5

Table 7 Environmental FA results after rotation.

	Factor 1	Factor 2	Factor 3
Y1	0	12	72*
Y2	− 2	57*	11
Y3	17	74*	20
Y4	53*	14	4
Y5	− 6	8	59*
Y6	46*	− 25	15
Y7	63*	− 3	4
Y8	78*	− 22	− 18
Y9	25	6	53*
Y10	34	− 62*	40

Figure 2 Reduced DMT.

Table 8 Linguistic variables for the rating alternatives.

Linguistic term	Fuzzy triangular number
Very poor (VP)	(0, 0, 1)
Poor (P)	(0, 1, 3)
Medium poor (MP)	(1, 3, 5)
Fair (F)	(3, 5, 7)
Medium good (MG)	(5, 7, 9)
Good (G)	(7, 9, 1)
Very good (VG)	(9, 1, 1)

Table 9 Criteria weighting by DMs.

	S1	S2	S3	E1	E2	E3	B1	B2	B3	B4	B5	B6
DM1	VH	MH	ML	H	VH	MH	VH	MH	VH	M	H	ML
DM2	M	VH	VH	VH	MH	M	VH	H	MH	VH	MH	H
DM3	ML	VH	M	H	ML	VH	VH	MH	H	VH	VH	MH

Table 10 Alternative ratings by DMs on sustainability subcriteria.

		S1	S2	S3	E1	E2	E3	B1	B2	B3	B4	B5	B6
DM1	A1	MG	VG	G	VG	VG	VP	G	VG	P	VG	MP	MG
	A2	G	MP	F	VP	MP	G	G	P	G	F	G	F
	A3	MP	G	MG	VP	VP	G	G	VG	G	F	G	MG
	A4	F	VG	MG	VG	MP	MP	G	G	VG	F	P	G
	A5	VG	F	G	F	MP	F	F	VG	P	VG	F	MG
DM2	A1	MP	G	G	VG	VG	VP	G	MP	MP	G	VP	MP
	A2	P	VP	F	VP	VP	VP	VP	VP	VP	P	MP	P
	A3	MP	P	G	MP	MP	F	G	G	F	MP	F	VP
	A4	G	VG	G	VG	VG	MG	F	VG	P	G	VG	G
	A5	G	G	F	G	G	F	G	G	P	VG	MP	G
DM3	A1	F	G	G	G	G	P	G	P	MP	F	VP	F
	A2	G	P	G	VP	VP	VP	F	P	MP	VP	F	F
	A3	G	MP	G	P	P	F	G	F	G	MP	F	MP
	A4	MP	F	G	VG	VG	G	G	VG	MP	VG	VG	F
	A5	VG	G	G	VG	F	G	G	F	MP	G	MP	F

Table 11 S′,R′ and Q values for each alternative.

	S′			R′			Q
A1	0.48	0.61	0.71	0.70	0.87	0.97	0.59	0.74	0.84
A2	0.69	0.88	1.00	0.62	0.82	0.99	0.66	0.85	1.00
A3	0.54	0.68	0.78	0.77	0.93	1.00	0.65	0.81	0.89
A4	0.29	0.37	0.42	0.41	0.51	0.56	0.35	0.44	0.49
A5	0.40	0.50	0.57	0.66	0.82	0.91	0.53	0.66	0.74

Table 12 Defuzzified values of S′, R′ and Q.

	S′	Ranking index	R′	Ranking index	Q	Ranking index
A1	0.60	3	0.85	4	0.72	3
A2	0.86	5	0.81	3	0.83	5
A3	0.67	4	0.90	5	0.78	4
A4	0.36	1	0.49	1	0.43	1
A5	0.49	2	0.80	2	0.65	2

Table 13 Analysis of v changes on alternative ranking.

V	Compromise solution
0	A4
0.25	A4
0.5	A4, A5
0.75	A4, A5
1	A4, A5,A1

Figure 3 Membership function of TFN.