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The Scope of the Bill of Labour

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Geoff Parkin shares his expertise in an exclusive article on Bill of Labour with WhichPLM. Geoff began working in the fashion industry in the ‘60s as a shirt cutter, and throughout the last 5 decades he has worked for companies including Lawtex, and Methods Workshop, and today serves as an experienced consultant for the garment industry. Geoff is an enthusiastic Manager, Industrial Engineer, and Mentor whose specialties include GSD training, and industrial engineering.

Throughout my decades of experience within the garment production industry, I’ve seen numerous changes – low cost computerisation, industry tailored manufacturing control systems, synthetic time data development systems, lean manufacturing, total quality management, just-in-time manufacturing, group working and more.

I’d like to take this time to discuss where all of this change leaves us with respect to the Bill of Labour. Quite simply, the bill remains the same but, taking into account all of the above changes, we can do so much more within it, just by adding a little more information. The Bill of Labour, is the simplest of terms, a list of operations required to complete a unit of production. The question, now, should be around what else the BOL could be or support?

Given the development of low cost, flexible software systems and database management systems with integrated databases the Bill of Labour can serve so many purposes and solve so many pre-production and production problems, whilst enabling management to exploit new techniques.

The key to wider use of BOL data is the scope and design of the database and how it links to the various functions within production. Each bill should first be uniquely coded so that it can be easily identified and retrieved for use; in addition the bill must contain ‘heading data’ which is specific to the product and the order this data can be modified to allow a number of calculations to be done.

The heading data could contain the following:

  1. A unique product identification code, which will ensure that a product is not confused with other similar products.
  2. Product name – the name that everyone refers to the product by – which can be a number, a name or a combination of both.
  3. Product description, containing enough information to cover all of the unique features of the product.
  4. Style Group, referring to multiple product types within a production unit or variations within the same product type such as fabric types. This function will allow the user to produce selective groups of listings when making comparisons.
  5. Production line reference. If the product is to be made within a particular line then a line reference can be cross-referred into a production line file to pick up information such as line capacity, line efficiency and line supervisor’s name.
  6. Customer reference, which can again cross-refer into a customer file containing contact and customer preference information.
  7. Quantity required per day. This information allows the subsequent operation information to be used to calculate the required number of operators required per operation to achieve the target production. There is a possible either/or option here; if the user inputs the number of operators available then it will be possible to calculate the number of units which can be produced. This is one of the benefits of low cost computing – at the planning stage it is possible to make “what if?” calculations before going into production.

To calculate the operation cost in minutes the bill must be linked to a master operation file. Each operation contained therein will be uniquely coded to avoid misunderstanding. Reference from the product to the operation file will ensure that if an operation time is changed it will automatically update within all styles using that code. Database management is a crucial function; all of those people affected by the data must have access to the live system, as out of date Bill of Labour hard copy listings can lead to serious mistakes.

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So, what should be contained within each uniquely coded operation data record? The following:

  • Unique operation code, which will ensure that an operation is not confused with other similar operations. Care must be taken in defining the code in terms of number of characters and types of character as changing this at a later date can lead to serious database problems.
  • Operation description. This should be accurate and concise, as all users must be able to understand what is meant by the description. Operation method is absolutely key to achieving quality and production targets; some operation databases are linked to a detailed methods description, which offers users the ability to fully understand what is meant. Production supervisors and line quality controllers can use the methods description to solve problems when production and quality targets are not met.
  • Operation standard time, which is the calculated time value for the specified method. Herein lies a problem: not every company specifies a detailed operation method and levels of accuracy of time standards can vary significantly. Specifying a detailed method is a function of the Work Study/Industrial Engineering department, bearing in mind the practical, technical and quality requirements. For a method to be valid it must be possible to train the operator to achieve it consistently. Calculating a time for a specified method is also the responsibility of the Work Study/Industrial Engineering department and this time should be as accurate as possible, given the techniques available for its calculation. The standard time for an operation is an emotive issue. Within piecework systems this represents money to the operator, and in a target driven system the operators in general must feel that they are being set reasonable targets. In both of these systems line management, production management and factory management are judged by the resultant production performance and efficiency levels within their areas of control – this can be more critical than with the operators. There are many techniques available for the calculation of production time standards (indeed too many to discuss here) – time study, company generated synthetic data, MTM based data systems, analytical estimating and historical data being the main methods. I have experienced all of these and have seen data produced by a synthetic data system used to develop a low operation time value regardless of the operator trainer’s inability to get the operator achieve the method. I have also seen “time studies” carried out without methods specification and without regard for operator effort. Accuracy is a paramount requirement but very hard to define. In terms of use of data within the Bill of Labour the time standards are the most critical; in terms of planning, loading and staffing what is important is not so much the accuracy of the data, but the ability of planning management to recognise the efficiencies which can be achieved using the data available.
  • Bundle handling standard time is a feature that is often combined into the operation standard time. If bundle handling time is treated as a separate value then there are some advantages to be gained. In cases where piecework values are printed on work tickets, the total operation value for the bundle/batch can be calculated and printed. This will be the operation standard time multiplied by the quantity within the bundle/batch plus the bundle handling standard time. When producing a Bill of Labour listing the average bundle/batch can be specified and the time standard will be the operation time standard plus the bundle handling standard time divided by the average bundle/batch size. In addition to this, if the bundle/batch handling system should be changed within any operation then the new bundle/batch time can be applied without the need to recalculate the operation standard time. One thing that must be noted is that the method for handling the bundle/batch must be specified and must be concise.
  • Operation standard minute value cost conversion code. For costing purposes a file containing a list of the various operation costs, such as sewing, pressing and packing rates, can be referred to by this conversion code. In this way costs for various grades of operation can be held and managed. A simple utility program can be used to modify the rates of conversion as appropriate and each time the bill is accessed the most recent cost will be available. Where piecework payment is to be calculated this will ensure that the most current conversion rate is used for pay; it would also be possible if desirable to print the monetary value for each complete bundle on the piecework tickets and, in the case of costing calculation, the most recent labour costs will always be available.
  • Operation type. This can be used to separate sewing, finishing and packing costs within a product listing and produce sub-totals for each function within Bill of Labour listings.
  • Loading category can refer to a skill centre or operation type and will enable the user to produce a spreadsheet-type report, listing styles to be loaded into production. The resultant calculation would show the percentage loading against each category, and at this point the planner could make “what if” calculations to establish the optimum load. The load category code would cross-refer to a load category file containing the name and capacity of each category.
  • Machine code. This code, ideally the asset number, would cross-refer to a file containing machine and equipment details such as description, serial number, machine speed and location and could be used to calculate the number of machines required for the completion of the product.
  • Attachment code. This would work in the same way as the machine code, and the maintenance department could administer both files.
  • Critical quality code. Again, cross referenced to a file containing each code such as A, B or C with descriptions of each such as Critical, Medium and Non-critical, these codes can be used to indicate to in-line QC inspectors a number of times to visit the operation during a working shift.

Provided that the above is in use then the Bill of Labour will enable better planning and introduction of products into production. The information generated would help in the pre-production planning meeting – a mechanic would have an equipment list, a manager would have a target and an initial line balance, quality control would be aware of the critical operations and be able to develop their inspection plan, and the line supervisor would be able to understand the task in hand. Of course a technologist, merchandiser and industrial engineer would also be present at this crucial meeting to answer questions on their contributions to the introduction of the style into production.

To remain competitive continuous improvement is key. Clearly being able to amend data within the Bill of Labour and immediately calculate a “what if” scenario will help managers in making there decisions regarding production. From the outset, loading styles using load categories will indicate where there are imbalances, which will prompt the industrial engineers to improve the method to alleviate the problem. Critical quality issues can be identified and new methods and attachments can be introduced to remove difficulties. The Bill of Labour, instead of being a simple statement of labour cost, can help management to respond to the demands of their customers.

Lydia Mageean Lydia Mageean has been part of the WhichPLM team for over six years now. She has a creative and media background, and is responsible for maintaining and updating our website content, liaising with advertisers, working on special projects like the Annual Review, and more.Joining mid-2013 as our Online Editor, she has since become WhichPLM’s Editor. In addition to taking on writing and interviewing responsibilities, Lydia has also become the primary point of contact for news, events, features and other aspects of our ever-growing online content library and tools.