Cutting is considered to be the most important operation in apparel manufacturing because firstly, it handles the costliest material resource – the fabric. Secondly, the spreading and cutting process is irreversible; the concept of repair or alteration does not work here. Further, and most importantly, due to over-emphasis on measuring sewing department performance, there is a sheer neglect of measuring the spreading, cutting and planning performance. This results in building up inefficiencies, leading to erosion of cost advantages
Cutting: The performance metrics in this department are mostly focused on fabric, the most expensive resource to track your factory cutting.
1. Material Productivity: This is an indicator of the output or value generated per unit of material used.
Material Productivity = [Output (value or unit or value added)]/ (Value of material used)
This is a fundamental re-examination of how, when and why materials are used. This measure shows how effectively material is used through the system. Any material left in the fabric store is also a waste as it will be disposed off at a much cheaper rate.
This is not a very common metric in garment industry but has been extensively used in textile industry. As per the PhD thesis “A Study of Productivity and Financial Efficiency of Textile Industry of India” submitted by Zala, Virambhai S to Saurashtra University in 2010; the average material productivity of textile industry is 4.07. This study was done on financial data of seven prominent textile companies of India.
2. Marker Efficiency: This is ratio of fabric actually used on the marker to total available fabric. Marker efficiency is calculated for one marker at a time and cannot be generalised for the entire order. This metric is mostly automatically calculated by CAD machines.
Marker Efficiency = (Area of marker used by garments)/ (Total area of marker)
Area of marker used for garment: The CAD system calculates the area of all the patterns placed on the marker.
Total area of marker: This is simple multiplication of length X width.
A marker efficiency above 80% to 85% is considered good. However, this value can vary depending on the pattern shapes (say bias skirts) and restrictions on pattern placements (say for stripes and plaids). This is an important indicator to decide on the quality of marker or whether by changing the position of the patterns the cad operator is improving on the marker or not.
It is often observed that 80% of the garments are cut by 20% of the markers. Therefore effort should be expended to improve marker efficiency of these 20% markers which can result in significant amount of savings.
One should note that the marker efficiency only states the quality of marker, there is still room for material wastage in a lay in terms of end loss, width loss and mismanaged end-bits.
3. Marked Consumption: Consumption of a garment calculated as per the markers made by the CAD department. In order to calculate this metric the following steps have to be followed.
Make cut order plan stating markers and no of plies for each lay
Make all the markers.
Calculate total length of fabric being used on the lays.
Divide this value by total garments to be produced.
4. Achieved Consumption: This is the actual consumption achieved per garment after the whole production process is completed. This requires extensive calculation but the results gives a realistic image of loss of material in the system.
Achieved Consumption = (Total Fabric Bought For Style)/ (Total Fabric In Garments Shipped)
The above formula will show final achieved consumption. The losses on material incurred by the whole factory in terms of dead stock, end bits and cutting room losses, part change and rejection in sewing, rejection in finishing as well as unshipped garments are included in this calculation.
If user wants to measure only cutting room achieved consumption then the formula should be slightly altered. Total fabric issued to cutting divided by total cut garments issued to sewing department will show the achieved consumption of cutting room.
5. Fabric Utilization: This is the ratio of fabric used on garments to fabric available to be used. This metric tells us the fabric utilization status of the entire order. Fabric generally costs 60% to 70% of the cost of the garment. Strict controls should ensure that every inch of the fabric is used properly and is accounted for.
Fabric Utilization = (Fabric Used In Garments) / (Total Fabric Available)
Total fabric available = Fabric allocated or bought for the order.
Fabric used on garment = This can be calculated in following ways.
Weigh one garment of each size ( garment should be weighed before sewing )
Multiply weight with number of garments cut in each size
Divide total weight by GSM and fabric width to get total meters used in garments.
Multiply Marker length with its Marker efficiency and number of plies laid in the marker.
The above calculation is done for each marker in the order and then sum of all gives the total meters used in garments.
The above will give fabric utilization for the order. The formula can be extended to calculate overall fabric utilization for the factory in a month.
6. Cut order plan: A cut order plan is effective if it uses least number of plies and least number of lays while cutting an order. An ineffective cut order plan can result in following losses:
Additional 4 cm to 6 cm end loss on every increased ply
Smaller markers may have lower marker efficiency.
Higher number of plies and lays result in more labour time in laying and cutting
Higher no of plies and lays may result in higher end bits and fabric wastage.
It is possible to calculate least number of possible plies and least number of possible lays for an order.
Least Possible Plies = (Total Order Quantity)/ (Maximum Pieces Allowed In a Marker)
Least Possible Lays = (Total Order Quantity)/ (Max. Pieces in a Marker X Max. Plies in a Lay)
It should be noted that it is always possible to achieve the above least possible numbers if the orders are properly planned. There may be slight variation of 1% in case of multiple colour orders. For some specialised cases like placement prints, this formula may not give the achievable solution.
The factory can compare actual with least possible solutions and check if their cutting room managers are following the above systems and using the available fabric in best possible way.
Follow these metrics in you factory and manage your fabric better, everyday.