Real Time Production Control
By Niki Tait FCFI(As previously featured in Apparel International)
The need to compete with low cost imports, shorter runs of production, more variety and shorter delivery requirements - all now bring increasing pressure on the apparel manufacturer who must have ever tighter control on his manufacturing costs.
In this special review, Niki Tait FCFI discusses how real-time software systems have special relevance and application.
‘REAL TIME’ in computer terminology is the updating of data at the time the event happens. For instance, if a customer phones up for a garment and the order is processed whilst the customer is on the phone, reserving the garment from stock, this is real time processing. A more common every day experience of ‘real time’ is the use of cash cards at a bank cash dispensing machine. Simultaneously we withdraw cash our account is debited.
‘Batch Processing’ in the other hand is a method of processing data ‘in a batch’ at a convenient time after the event. An example known to all clothing and footwear manufacturers is the common form of processing of shop floor production information. Here bundles of work are identified using tickets. Self-adhesive operation stubs represent each operation the bundle moves through. The operator responsible for a particular operation removes the appropriate stub once she has complete the bundle and this is stuck on to her daily work sheet. Also recorded on this sheet is any ‘off standard’ time she may experience during the day.
At the end of the day the daily work sheet will have recorded on it all work carried out by an operator during that day, together with details of any down time. The work sheets for all the operators are collected up and given to the office for subsequent processing. This is normally carried out the following morning.
With most batch production control systems the information fed in from the work sheets will update information regarding the labour cost, work in progress movements and gross wages. Information about these is, therefore, by necessity, only accurate up to the close of business the day before – i.e., yesterday.
The use of ‘real time’ in production control is accurate up to the last bundle processed by any operator. As with batch production control, tickets or some other means of work identification accompanies each bundle of work through the production process. Instead of stubs being removed from the ticket and stuck on to a work sheet, information is read into the computer immediately the bundle is completed at each workstation. A terminal is, therefore, required at each workstation. These terminals do not need to be VDU’s and keyboard, but some type of appropriate input devise, which are normally small numeric keypads, often resembling pocket calculators with or without bar code readers attached as appropriate.
Real time systems from different software houses all differ slightly in operational terms, but in general each style has an operation route entered against it listing the sequence of operations in which the garment will be produced. Each operation will be allocated standard minutes, which may or may not vary according to the size of the garment. The order is entered giving details of the colour/size quantities. As each lay is cut tickets are produced against the actual cut lay details.
In a knitting factory, tickets will be printed prior to knitting a batch and knitting will become an operation monitored by the system. The nature of a knitting machine allows for data to be captured direct enabling each machine to be automatically monitored.
Tickets for the order are then printed. As the work is bundled the tickets will be attached to the bundle giving details including style, order number, colour, size, quantity in the bundle and probably the sequence of operations with the allocated operation numbers. As operators arrive at work they will clock in at the terminal situated at their workstation. As they complete each bundle of work they will record the detail into their terminal.
A range of alternative input devices used in a system supplied by XeBusiness Ltd.
Depending on the system used, there are various alternative methods. With some the operator will tell the system which order and operation she is working on and then only record the bundle number each time until either the order or the operation she is doing is changed. Another method is where each bundle has a unique number, which denotes the order, operation and bundle she is working on.
With all systems once the computer has this information it will automatically know the style, quantity, colour and size of that bundle.
The system will prompt the operator for the information it needs, when it needs it.
Off standard time will also be entered via these terminals, normally by a supervisor, who will enter her clock number or password and then the operator’s number together with the code for off standard. Time is not entered as the system has a continuously running clock and as soon as off standard is entered the operator is logged off at that time and back on again once work is available.
At the end of the day the operator clocks out again using her terminal. Pay rules for each category of off standard are known by the system, as are yield rates for each operator or operation as relevant. Overtime payment rules are also held.
The basic set up information that each specific system requires will differ, though in summary will tend to include:
As discussed, work will be identified by self generated tickets from the production order information, in normal printed or bar coded form and will identify contract, customer, style, order, size, colour, quantity and operation as relevant. The facility to increase or decrease bundle quantities should be present with the increase facility only assessable by a supervisor, not an operator. A facility whereby tickets can contain special instructions can be useful as a means of communication to the shop floor. These instructions will normally be printed on to the top of each ticket, the ‘ticket header’ and may contain special quality points, which trim or components to use, packaging instructions etc. These instructions are usually held against the style details, allowing an editing facility at order level, useful, for example, if the tickets are printed after a bad cut has been found, e.g.; ‘PLACE POCKET ˝" TO THE LEFT OF DRILL HOLE.’ ‘SLEEVE HEAD NIP MISSING – SEE SUPERVISOR.’
Up-to-the-minute accurate information available from a real time production system will include details about:
Work in Progress. Normally available will be data by contract, customer, style, order, size, colour, bundle and delivery date. Analyses of this information will be available in various levels of detail – for example, quantities ordered, issued, completed and faulty; progress points; individual operation and individual operator. Valuations of the work in progress are also usually available.
Labour Cost Control. Typical data will include attended time; overtime; off standard time; standard minutes earned on and off standard; performance on and off standard; efficiency; utilization; excess cost by category and total; quantities produced on and off standard and totals; actual cost per unit; build up to gross pay by category and total gross pay; automatic calculation of average hourly rates using appropriate calculations; skills inventories. Analyses will be shown at various levels of detail for individuals and by supervisor, team, section, and factory. Systems should normally be able to cater for different methods of payment systems, for example, piecework, team and/or factory bonuses and where relevant a mixture of payment systems within a factory.
All the foregoing details will also be available from a good batch production system, though as discussed above, by necessity this information will only be accurate to the last time of input. Additional information that is only available using real time often includes:
Although all these additional facilities are extremely useful to supervisors and management alike, the key benefit must be the on line motivational feed back of information to the operators and often this feature alone will result in a quick pay-back for the investment required for these systems.
XeBusiness (formerly Kewill-Xetal), the major supplier of real time systems in the UK, provide 29 categories of information available to operators through an LCD style display on the workplace keypad. This information includes: name of operator clocked on to the terminal; attended time so far today; total pay earned so far today; current category of pay, i.e.; whether on or off standard; efficiency so far today; on and off standard performances so far today; current performance on this bundle; predicted pay at the end of the day dependant on efficiency so far; predicted pay to the end of the week depending on the current situation to date this week; individual actual pay for each day of the week; current order and operation number, operation description; standard minutes for the current operation; any special bundle allowance applicable to the current bundle; any standard minute or time allowances operational; the number of the last bundle claimed; quantity and standard minute value of current bundle being worked on; number of standard minutes produced in total and on standard.
The management of each individual factory can determine whether all, or a selection, of these enquiries are available through the keypads to the operators.
In this factory Captor keypads are used to collect real time data from teams and to feed back information to the team. Only one terminal per team is required.Right, for collecting 'off line' data about completed garments, the captor terminal light pen can be used to read bar codes. A unique pack code prevents double booking. Labour cost and work in progress files are immediately updated.
Real Time Advantages
Using the facilities of real time and acting quickly on the information that is made available can produce many benefits for the manufacturer. The exact nature and degree of relevance of these will depend on the circumstances of each individual company and the actual facilities available from specific systems. Experience shows that advantages over batch production control are likely to be encountered in the following areas:
Increased Productivity - leading to an addition in the number of standard minutes available for manufacturing. Although prime costs per product remain fixed, overheads remain constant. Therefore the unit costs reduce and all contribution on additionally produced garments becomes increased profit. Increased productivity results from three areas as follows: -
(1) Increased performance of operators (normally a minimum of 5%) mainly due to the increased self-motivation resulting from the immediate feed back of performance and wage information. Further reasons include better selection of operators for operations due to improved management information.
(2) Increased utilisation (10% should be achievable) of operators and machines due to quality data for use in line balancing and immediate feed back of information high-lighting potential danger areas.
(3) Reduction in standard minute values (0.1sm minimum per bundle) due to a reduction in time spent booking work. Identification of loose rates is quicker and easier. Data on performances on each individual bundle is normally available providing much useful management information in this area.
Improved Quality Control - due to the ability to identify immediately, not only those operators who are causing faults, but also those who, whilst carrying out subsequent operations, fail to notice the problem. Facilities normally allow for the tracking of rejects/rework and provide much of the documentation required by BS5750. On line performance data clearly identifies to operators how their performance drops whilst they stop producing to carry out their repairs, reinforcing the managements argument that it is more cost effective to each operator to produce good work in the first instance.
Improved Contract/Style Costing. Real time is a method of cost effectively and accurately allocating excess costs directly to the bundles, operations, orders and styles, even to the size and colour for which they are attributable. True actual verses standard costs can therefore be measured and precise information can be used as a basis for costing in the future.
Reduced Labour Turnover and Absenteeism. By using the feed back from the terminals, operators not only achieve higher performances and thus higher wages, at no additional cost to the company, but they also learn how to pace themselves better through-out the day, thus reducing fatigue. More effective and controlled management, together with an increased level of security, results in reduced labour turnover and absenteeism.
Reduction in Clerical and Wage Costs. Gross wages are automatically calculated by the system requiring minimum wage costs. In any system requiring an aspect of manual calculation, inaccuracies will inevitably occur. Where these favour the operator they normally go uncorrected. Where wages are calculated automatically, this not only reduces the manpower required for this function, but inaccuracies are reduced: in some cases this amounts to a minimum ˝% of the wage bill. With the built-in safeguards of a real time system overbooking of both work completed and off standard time will be reduced. This may amount to 1% minimum of the wage bill.
Reductions in Work in Progress, Bottlenecks, Late Deliveries, Overtime and Progress chasing. These reductions are due to more accurate and up to date information for management to act upon; and in turn can lead to reduced throughput times, increased flexibility, faster deliveries, release in capital employed, reduction in borrowing and space requirements, reduction in freight costs and more profitable sales.
With the increasing interest in Team Work, XeBusiness have developed a modified real time system to cater for this alternative method of manufacturing. Instead of each operator requiring a terminal, one terminal per team is used to collect and feed back data from and to the teams. The first such system is now operational at J.A. Hickey and Co. Ltd in Ireland. This factory has a mixture of team working and conventional production methods and the real time system caters for both simultaneously.
Another example of where real time is integrated with the manufacturing method is with unit production systems such as Eton. Here instead of tickets accompanying the work, the individual garment carriers have a bar coded identification which distinguishes the work completed at each workstation.
Integrated Real Time
As will all production control systems, further benefits are expected to result when independent systems or modules are integrated together. When considering the implementation of a new manufacturing system we need to ask the question: ‘What control systems do we need to run our company and all our resources, efficiently and profitably in line with our current and future aims and objective?’
This question leads us to extend our thoughts to include materials, finished goods, order processing, sales forecasting, capacity planning and scheduling, costing and even payroll and ledgers. A fully integrated business solution appropriate to our needs, which can be phased in, if required, to address the key priorities of a company must be the favourite.