Industrial Engineering (IE) Formula for Garments Industry

 

01. Target = 60 ÷ ( SMV x No. of worker x working hour x expected efficiency) .

02. Target = 60÷SMV.

03. Team target =(60÷SMV)x Present operator x Organization efficiency .

04. Target per day = Working hour x 60 x No. of operator / Target SMV.

05. Capacity=Average of total obserb time x 1.66 + 30% Allowance / 60.

06. Factory capacity=No. of operator x working minutes + Present % x average factory efficiency.

07. Capacity per day = Present operator x working hour x organization efficiency x Attendance.

08. Weekly capacity = No. of operators x Absenteesm x Clock minutes per week x Average factory efficiency.

09. Marker efficiency = Area of patterns in the marker / Total area of the marker x 100.

10. Load = (Contract size x work content) contract 1+ (Contract size x work content)

Contract 2 + etc.

11. Load = Order quantity x Work content (SMV of garments).

12. Observe time = Total cycle time / No. of cycle.

13. Basic time = Avarage of observe time X Rating %.

14. Sam = Basic time x Allowance.

15. Rating = Observe time x Standard rating / Standard rating.

16. Cycle time = 60 / Team target.

17. Pitch time = Total SMV / Present operator.

18. Efficiency = Earn hour / Available hour x 100

19. Efficiency = SMV / Total time.

20. Earn hour = (Production x SMV) / 60.

21. Available hour = Working hour x Use machine(Total manpower)

22. Performance = (Earn hour / Available hour – Off standard time) x 100.

23. Improvement = 1-(Production / Capacity).

24. Balancing efficiency = 1-Balancing loss.

25. Loss pcs = (60/SMV)x Available hours x avg factory effi (61%) -Q.C Pass

26. Balancing loss = AML-TML/AMLx100.

27. Standard time = Net operation time x (1+ Ratio of loss time).

28. Daily output = Working hours (seconds) + Standard time.

29. Output per operator = Work hours (second) / Total time of operations.

30. Required No. of operators = Targeted daily output / Daily output per operator.

31. Target daily capacity = Daily work hours / Standard process time (SPT).

32. Daily capacity per worker = Daily capacity / No. of workers = Daily Work hours / Standard total processing.

33. Organization efficiency = Pitch time / Bottle neck process time (x100) = 100/140 x 100 = 71.4%

34. Upper limit = Pitch time / Target organization efficiency = 100 / 0.85 = 117.6 seconds.

35. Lower limit = 2 x Pitch time – Upper limit = 2 x 100 – 117.6 = 82.4 seconds.

36. Planned daily work flow = Daily work hours / Standard process time (SPT) x organization efficiency.

37. Accumulated avarage time = Daily work hours/AccumulatedxNo.of daysxstandard No.of workers in

The group/No. of pieces produced.

38. SMV = Basic time + Allowance time + bundle time.

39. DHU = No. of deffect observe / No. of garments checked.

39. Booking fabric K.G. = Order quantity / 12 x Fabric consumption per doz.

40. Garments K.G. = Total receive fabric kg – (Save return kg + Jhute kg + Wastage fabric kg)

40. Input to sewing pcs. = Total in pcs – (Print Embroidery short & wastage + Cutting wastage pcs.)

39. Fabric consumption (CM) = Length x chest x 2 x GSM / 1000 / 10000 x 12 + Wastage%.

41. Fabric consumption (Inch) = Length x chest x 2 x GSM / 1000 / 1550 x 12 + Wastage%.

Formula#1: Calculating the daily production target of a line

Daily Line Target = (Total shift hours X 60 X No. of operators in a line X Line Efficiency%)/Garment SAM

 

Here is an example to understand this calculation. 

Daily shift Hours of a factory = 8 Hours

Number of operators working in that line= 30 operators

Average Efficiency of that line: 60% 

Garment SAM: 20 Minutes

 

Production target of this line (Daily) = (8 X 60 X 30 X60%)/20

                            =(480 x 30 x60) / (100 X20)

                            = 432 Pieces 

 

Formula#2: Operator-wise production target calculation 

Individual operator target = (Total working minutes in a day X Line Efficiency %)/Operation SAM

 

In Formula #1, you have the formula for calculating the daily production target for a line. 

But operators working in that line will be working on different operations and the SAM of those operations will be different. 

 

So, you need to calculate individual operator targets as well based on Line efficiency and operation SAM. 

 

Refer to this example for the calculation operator target for the specific line.  

 

Factory shift: 8 Hours (480 Minutes)

Line efficiency = 60% (considering it is the same line in formula#1)

Operation SAM: 0.5 Minutes

Production target of that operator: (480 Minutes x 60%)/0.50

                = (480 X 0.60)/0.5

                = 576 Pieces per 8 hours per day.

 

In case you use operator performance level (efficiency%) and operation SAM and calculate the production target of that operator, the result is called the operator's production capacity.

Normally, an operator-wise target is not given based on the individual operators' performance, instead, it is calculated based on the line efficiency. See the below example of the operator's capacity. 

 

Factory shift: 8 Hours (480 Minutes)

Operator efficiency = 80%

Operation SAM: 0.5 Minutes

Production capacity of that operator: (480 Minutes x 80%)/0.50

                = (480 X 0.80)/0.5

                = 768 Pieces per 8 hours per day.

 

 

Formula#3: Calculating operator efficiency

Individual operator Efficiency% = (Units Produced X Operation SAM X 100)/Total minutes worked

 

When you develop the skill matrix for sewing operators you need to measure individual performance. 

Secondly, if you plan to start a performance-based incentive scheme for the individual operator, measuring individual operator efficiency is essential.

 

Example: 

Let's say you need to calculate the efficiency of an operator based on the last production day's data. 

Operator Produced total unit: 500 pieces 

SAM of the operation: 0.60 Minutes

The operator worked: 480 Minutes (full shift hours)

 

Operator Efficiency     = ((500 x 0.60)/480 )X100 

                                       =(300/480)*100

                                       =62.50%

 

Formula#4: Line efficiency

Line Efficiency% = (Line output X Garment SAM X 100)/(Number of operators X Minute worked in a day)

 

Note: Include helpers and workers doing manual operations in case you have included SAM of those operations.

 

Example:

Line A produced 600 units (Style Z)

SAM of style Z is 20 Minutes

Attendance in Line A = 30 Operators

Shift Time: 8 Hours

 

Line Efficiency (Overall Efficiency%)= (600 x 20 x 100)/(30X8 x60)

                                                    = (1200000/14400)

                                                    = 83.33%

 

Here is another example of line efficiency calculation.

Note: include helpers and workers doing manual operations in case you have included SAM of those operations

Formula#5: Machine productivity

Machine Productivity: (Line output / No. of machine used in producing those garments) 

 

Machine productivity is measured in production per machine per shift day. I have discussed more about machine productivity calculation with examples.

 

Example:

Considering Line A has production of 600 units. 

Numer of sewing machines used: 27 Machines

 

Machine productivity:

                        =  (600/27)

                        = 22.22 units per machine 

 

Formula#6: Labour productivity

Labor Productivity = Line output / No. of total manpower (operators +helpers)

Example:
Considering Line-A has production of 600 units
Numer of sewing operators used: 30 and helpers 5. Therefore labor productivity
                = (600/35)
                = 17.14 units per labor

Formula#7: 

Line WIP (work in process) = Total pieces lying on the line for a particular order line 

 

WIP of the line of an order is equal to the total pieces loaded till date minus Total pieces out till date.

 

Formula#8: 

Standard Time = (Observed time X observed rating) + Allowances

Allowances – Relaxation allowance, contingency allowance

Formula#9: 

Machine utilization% = (Actual Machine running Time X 100) / Time available

Formula#10: 

Cost per minute = Total cost incurred in labor / Total available working minute in a day X no. of labors

Formula#11: 

Production Cost per unit = Total cost incurred in production in a day/ no. of garment produced in a day

Formula#12: 

Man to Machine ratio = Total manpower of the factory / Total no. of sewing machines (utilized)

 

24 Industrial Engineering (IE) Formula for Garments Industry

01. Determination of SAM (Standard Allowed Minute): SAM = (Cycle Time × Performance Rating) + Allowances

• Cycle Time: 75
• Performance Rating: 75%
• Allowances: 10
• SAM (Standard Allowed Minute): 1.10

02. Determination of SMV (Standard Minute Value): SMV = Cycle Time × Performance Rating

• Cycle Time: 30
• Performance Rating: 85%
• SMV (Standard Minute Value): 0.43

03. Determination of Earned Minute: Earned Minute = Total Production X SMV

• Total Production: 1700 pcs
• SMV: 5.20
• Earned Minute: 840.00

04. Determination of CPM (Cost Per Minute) CPM (Cost Per Minute) = Monthly Factory Cost/Monthly Earned Minute

• Monthly Factory Cost: 12000000
• Monthly Earned Minute:1120000
• CPM (Cost Per Minute):10.71

05. Determination of CM (Cost of Manufacturing): Cost of Manufacturing (CM) = SMV × CPM

• SMV: 5.5
• CPM: 10.7
• CM (Cost of Manufacturing): 58.85

06. Determination of Daily Line Target   Daily Line Target = (Working Minute × Manpower × Efficiency)/SMV

• Working Minute/Hour: 600 Minute
• Manpower: 35
• Efficiency: 50%
• SMV: 7.8
• Daily Line Target: 1346

07. Determination of Individual Operator Target: Individual Operator Target = (Working Minute × Manpower × Efficiency)/SMV

• Working Minute/Hour: 600 Minute
• Manpower: 1
• Efficiency: 60%
• SMV: 0.25
• Individual Operator Target: 1440

08. Determination of Line Efficiency: Line Efficiency = (Line Output × SMV × 100)/ (Manpower × Working Minute)

• Line Output: 2200
• SMV: 12.5
• Manpower: 60 persons
• Working Minute/Hour: 700 Minute
• Daily Individual Line Target: 65%

09. Determination of Individual Operator Efficiency: Individual Operator Efficiency = (Line Output × SMV × 100)/ (Manpower ×Working Minute)

• Line Output: 1400
• SMV: 0.3
• Manpower: 1 Person
• Working Minute/Hour: 600 Minute
• Individual Operator Efficiency: 70%

10. Determination of Production Cost Per Unit: Production Cost Per Unit = Total Production Cost/Total Production Pcs

• Total Production Cost: 72000
• Total Production Pcs: 1500
• Production Cost Per Unit: 48                                       

11. Determination of Machine Productivity: Machine Productivity = Total Output/Total Machine

• Total Output: 2000
• Total Machine: 25
• Machine Productivity: 80

12. Determination of Labor Productivity: Labor Productivity = Total Output/Labor (Manpower)

• Total Output: 1500
• Labor (Manpower):  32
• Labor Productivity: 47

13. Determination of Machine Utilization (%): Machine Utilization (%) = (Actual Machine Run Time X 100) / Total Time

• Total Time: 600
• Actual Machine Run Time: 400
• Machine Utilization (%): 67%

14. Determination of Man to Machine Ratio (MMR): Machine to Machine Ratio (MMR) = Total Manpower/Total Number of Machines

• Total Manpower: 4000
• Total No-Idle Machine: 2600
• Man to Machine Ratio (MMR): 1.54

15. Determination of Monthly Factory Capacity: Factory capacity = (Working Hour × Total Worker × Working Day × Factory Efficiency × 60)/Avg. SMV

• Working Hour: 10
• Total Worker: 2500
• Working Day: 27
• Factory Efficiency: 55%
• Factory Average SMV: 5.5
• Factory Capacity: 4050000

16. Determination of Cut to Ship Ratio: Cut to Ship Ratio = (Total Shipped Quantity/Total Cut Quantity) × 100

• Total Shipped Quantity: 4000000
• Total Cut Quantity: 4080000
• Cut to Ship Ratio: 98%

17. Determination of Cut to Ship Loss: Cut to Ship Loss (%) = [(𝑇𝑜𝑡𝑎𝑙 C𝑢𝑡 Qty.- 𝑇𝑜𝑡𝑎𝑙 Ship Qty.)/ 𝑇𝑜𝑡𝑎𝑙 C𝑢𝑡 Qty.] × 100

• Total Shipped Quantity: 4000000
• Total Cut Quantity: 4080000
• Cut to Ship Ratio: 2%

18. Determination of Total Financial Saving: Total Financial Saving = Number of Extra Pieces Shipped × Average FOB

• Number of Extra Pieces Shipped: 1000
• Average FOB: 4.5
• Cut to Financial Saving: 4500

19. Determination of DHU (Defect Per Hundred Unit): DHU = (Total Number of Defects Found × 100)/Total Pieces Checked

• Total Pieces Checked: 1100
• Total Number of Defects Found: 85
• DHU (Defect Per Hundred Units): 7.73

20. Determination of Pitch Time: Pitch Time = Garments SMV/No. of Operations

• Garments SAM: 9.8
• No. of Operation: 25
• Pitch Time: 0.39

21. Determination of WIP (Work in progress) = Total input- Total output (cutting/sewing/finishing)

• Total input: 1775 pcs
• Total output: 970 pcs
• WIP: 805 pcs

22. Determination of RFT (Right First time) = (Number of pass goods or Lot / Number of total produced goods or Lot) x 100

• Total pass: 195 pcs
• Total Produced: 203 pcs
• RFT: 95.06 %

23. Formula of calculating Defective Rate = (Total defective garments /Total inspected garments) *100

• Total defective garments: 17 pcs
• Total inspected: 307 pcs
• Defective Rate: 5.53 %

24. Formula of calculating Defects Rate = (Total defects /Total inspected garments) *100 (One garment may have more than one defect)

• Total defects in inspected garments: 22 pcs
• Total inspected: 307 pcs
• Defects Rate: 7.16 %