Differing Plastics Flavors
Written By: Predrag Jakovljevic
Published On: September 06 2006
Plastics products in 2002 ranked fourth among the top manufacturing industry groups in shipments—behind only motor vehicles, petroleum refining, and electronic components and accessories. Comparative growth rates suggest that productivity in plastics manufacturing grew about 1.2 percent per year from 1980 to 2002, which was almost equal to the productivity growth rate achieved by manufacturing as a whole. Yet relatively few major enterprise applications vendors have chosen to target this industry with industry-specific systems, capabilities, or modules. Specifically, rather than focusing on the special requirements of the industry, the vast majority of enterprise resource planning (ERP) and supply chain management (SCM) vendors have chosen to develop software solutions that address mostly those needs that plastics manufacturers and distributors have in common with other discrete manufacturers and distributors. For more information on this, see The Tricky Enterprise Applications Needs of Plastics Producers.
Part Two of the series The Tricky Enterprise Applications Needs of Plastics Producers.
To make things even more difficult, there is no one simple process used when manufacturing plastic products, since the manufacturing methods depend on the final product. Thus, the primary plastic manufacturing processes consist of
- injection molding
- plastic extrusion
- extrusion blow molding
- injection blow molding
- stretch blow molding
- thermoformed plastics
As an injection molder, a user enterprise may have both process and discrete manufacturing requirements, and one of many complexities of an injection molding operation lies within monitoring costs. Namely, an enterprise may produce biomedical devices, optics, computer components, consumer electronics, automotive parts, or other injection molded products. But the bills of manufacture (which go beyond conventional bills of material [BOMs] by also including bills of operations) must help it consider cost inputs such as materials, return of regrind to inventory, scrap, labor and workstations rates, machine setup, tooling, sub-contracting, and warehousing, throughout their operation.
To delve deeper into some intricacies, the software has to be able to handle multiple cavitations and "family tools," where the vendor IQMS excels. In other words, plastic producers want and should be able to make more than one unique part per machine cycle. Although this might sound basic, generic ERP vendors typically use the concepts of "by-product" or "co-product" to handle this, which is a sign that this is an afterthought rather than a native way to proactively manage family and multi-cavity tools. This is not to mention the need for handling standard and actual cavitation (in other words, with some blocked cavities, whether this is done on purpose or not), which vouches for the creation of complex molding tools. Other tricky "must have" capabilities entail the system's aptitude to adjust cavities (either per item or as a total number) used in the mold as conditions change, and to track different costing at individual plant locations using multiple BOMs for the same item.
Another requirement is the capability to track scrap and regrind for material reuse purposes, since as a rule, the molding process generates reusable material with each cycle. It is crucial for a system to handle this in terms of material resource planning (MRP) and other planning requirements, as well as for on-floor tracking and valuation. Another important feature is related to handling consumed excess material (called runner and sprue) that may or may not be reusable. In other words, how do users accurately cost a single part if they are making many different parts at the same time, and how do they allot the excess material to each part correctly when trying to figure out how much material a job will consume? Normally, generic ERP systems simply take the part weight, multiply it by the number of cavities making it per cycle, factor in some scrap rate, and thus quickly predict how much material will be consumed. However, that is often suboptimal in the plastics injection world.
Other Plastics Requirements
Plastics manufacturers also want to capture complete costs for all materials, labor, overhead, and work-stations within the quotes, and to easily convert their quotes to a BOM. In addition, to ensure accuracy, they often have to attach drawings and specifications to sales orders, BOMs, and work orders. Quotes and BOMs have to be able to support family tools, with part costing and pricing for individual items of family molds. Cost calculations must take into account materials, purge, labor, overhead, stations, packaging, setup, tooling, sub-contracting, and warehousing. Other frequent requirements include generation of multiple product configurations (including quantity, run rate, scraps percentages, and so on) per BOM for what-if scenario purposes, and conversely, multiple BOMs for the same item.
Additional nice-to-haves (if not givens) include graphic visualization of costs, the ability to view all BOM components in tree format, and easy management of BOMs with utility programs (for example, whereby users can mass copy multilevel BOMs, and perform cost-rollups, where-used, search-and-replace, and materials price pass-through). Furthermore, the users must be able to perform mass updates of their BOMs with replacement items for obsolete and unacceptable or defective materials. Then, users should be able to change or add additional cost components within their BOMs, or if the price of materials like resin increases, they should be able to run a utility program to update all of their BOMs with the new cost. As for the supplier contract pricing tables and product price lists, users have to be able to create quantity price break tables with margins automatically from the BOM. Needless to say, all associated price changes should be produced too, while all calculations should pervasively and interchangeably be done in multiple units of measure (UOMs).
The planning process takes into consideration tool setups, family molds, and tool conflict resolution, as well as set-up and tear-down times and preventative maintenance. As for the important issue of shop floor scheduling, these ERP systems should feature an intuitive (for example, drag-and-drop) scheduling control center, so that it is easy for users to schedule all their jobs, at all levels of BOM or operations, on just one screen. They should be able to instantly see where sub-component and assembly jobs are scheduled, and if they choose to reschedule a job on a different date or move it to another workstation, the scheduling control center must automatically reschedule all associated lower-level jobs to help the users meet their promised shipping dates.
In addition, scheduling must help with gaining visibility into machine setup and teardown times, preventative maintenance, tooling, and raw material shortages, and it must also account for tool setups, family molds, and tool conflict resolutions. Last but not least, scheduling tools must provide visibility for out-of-service tools or dies, with an auxiliary equipment conflict evaluator.
It is thus no small wonder that only a handful of plastics-oriented ERP systems have been designed to manage such high production rates and repeatable processes, including single- and multi-cavity molds, family molds, mold or machine matching, inter-level scheduling challenges, and inter-branch (facility) scheduling. Scheduling of multiple unique part numbers in a single cycle on a single machine is another fatal flaw. For example, if one has to make three unique part numbers in a single cycle on a single machine, the system has to be able to create a work order for each part, and schedule all three parts at the same time on the same machine. General purpose ERP solutions typically require separation of item number, order numbers, and so on.
The Challenges of Plastic Extrusion
As for catering to plastic extrusion environments that manage the production of continuous sheeting, film, tubes, pipes, rods, profile shapes, and coating wire, cable, cord, or other detailed extrusion operations, the software has to be able to schedule many secondary operations, such as co-extrusion or dual extrusion. In other words, it has to be able to use the plastics-specific BOMs to monitor costs and schedule fabrication processes such as cutting, notching, drilling, punching, routing, gluing, embossing, pad printing, silk screening, hot stamping, assembly and more. Users should be able to allocate costs evenly across their operations and factor in "wait" states for cooling operations when scheduling jobs (at various levels of bills of manufacture) as well as the setup time for new jobs. Like their other plastic manufacturers brethren, extruders also have to be able to leverage plastics-specific inventory management tools to keep track of materials at multiple warehouses and locations, or manage lot codes and serialized inventory. For instance, they might want to produce consistent lot-to-lot colors, and to track lot code, serial, and location on all production runs.
Whether users are purchasing materials or entering a sales order, they have to be able to assign multiple UOMs to individual inventory items, whereby the ERP system will calculate conversion quantities, thus relieving inventory in the base UOM. In other words, users should be able to define the units of measure (for example, pounds, linear feet, sheets, or inches), and the astute ERP systems should do the rest (such as handling raw materials in pounds and finished goods in multiple UOMs). Furthermore, each customer usually wants to be invoiced in its preferred UOM (for example, pieces or eaches, pounds, hundredweights, lots, kilos, and more), and the software should be able to convert these into others based on material characteristics such as specific weight or density.
In addition, for certain companies it may be desirable for plastics-oriented ERP systems to provide visibility into the inventory quantities that are marked as quality control (QC) hold while the product is being evaluated for dimensions, color, wall thickness, and more. These companies also require software that can quickly configure quotes and orders based upon exacting customer specifications, and recognition that inventory is multi-dimensional and multi-faceted is again paramount for proper inventory management. When the user company offers products in different dimensions (such as length, width, thickness, and diameter), the software's formula engine should be able to ensure the validity of the configured items, and to deliver convenient cost-plus pricing capabilities that allow users to associate profit margins with materials, and labor or overhead for configured items.
Additionally, customers will often have specific labeling requirements, packaging requirements, and material handling capabilities. Often, they will require detailed certification or test reports, and if the selected software solution cannot handle these inventory and document management requirements seamlessly, the hidden administrative costs will quickly erode the user company's profit margin. The other features that illustrate the vendor's intimate understanding of the extrusion processes would be part weight calculations, regrind management, handling packaging options, and handling work station, die, or item relationships.
Blow Molding Requirements
As for the unique demands of extrusion blow molding, injection blow molding, stretch blow molding, and other blow molding processes, the plastics-specific solution must be able to aptly help users manage all of their process steps, including extrusion, pinch-off, blowing, and cooling. Customers within the blow molding niche use plastics-oriented ERP systems to manage the production of such products as bottles for household, food and beverage items, containers for industrial goods and chemicals, tanks, car bumpers, and more. Such a system should be able to help users manage accompanying build-to-stock processes with minimum and maximum reorder levels, and identify them in the BOM, whereby the schedulers can then create and schedule jobs based on standard stock levels or custom orders.
As with some of the abovementioned plastics producers, blow molders need accurate cost capturing capabilities, and the plastics-oriented BOM modules must help them manage secondary operations such as label application and silk screen printing services (for in-plant and outside processing) for both scheduling and costing purposes. Along similar lines, users often have to attach drawings and specifications to sales orders, BOMs, and work orders to ensure accuracy in the use of a wide variety of materials, neck finishes, and colors. Then, like their injection molder counterparts, blow molders should benefit from a system that can make it easy to schedule all their jobs, at all bills of manufacture levels, on just one screen, bearing in mind considerations like job setup and tear-down times, tooling options, mold or molding machine matching, regrind management, and so forth.
The next kind of plastic producers would be those featuring blister packaging, vacuum-formed, pressure-formed, in-line extrusion and forming, and other thermoformed plastics processes, where the enterprise applications provider has to understand their desire to achieve the right product thickness, accurately reproduce molds, capture costs, and again, convert materials into alternate UOMs. As they produce automotive parts, food containers, and consumer, medical, and electronics packaging, these potential users need such functionality as web and index calculations, part weight calculations for the BOM, costing capabilities to the fifth decimal place (or more if necessary), case packs and costing for thousands as a base unit, web-based ordering (again in multiple UOMs) and tracking, and so on.