The United States has made a trillion dollar investment in computers in the past 10 years. The decision to make this investment, which is greater than the total investment in the pre-war (WW II) US manufacturing infrastructure and the interstate highway system combined, was not debated or even discussed, nor was it approached systematically: it just happened, one minuscule marketplace decision at a time.
These decisions are rapidly creating a deep polarization of society, and a new class system, based on "computer literacy". The cost of this split has been, and continues to be, enormous. Skills learned only a year or two ago are rendered obsolete by changes in software and operating systems. The cost of equipment is rarely recovered before the equipment is rendered obsolete by rapidly evolving technology. Computer salvage yards are nearly as sobering as automobile wrecking yards.
In large corporations, computers linked through local area networks (LANs) have been integrated fairly effectively. In smaller companies and public agencies (especially hospitals and government bureaucracies) the benefits have often been harder to identify. For the public, and the schools, it has often been a financial bloodbath.
Computers have been "sold" to (or more accurately, pushed on) the American public over the last ten to fifteen years based on a number of promises that have generally failed to materialize. The most compelling promise has been getting more work done faster. Actual results have been quite the opposite. In return for an enormous investment of time and capital, we have generally found that computers function as roadblocks as often as accelerators. If a rigorous analysis is done, it will be seen that many things take longer, and that although the quick got quicker, the slow got slower.
For much of society it has been a catastrophic waste of time and effort. Part of the reason for this is that the technology itself has not evolved in a linear way. Instead, it leapfrogs. Another part of the problem comes from the enormous gap between fact and expectations: people who decide to computerize their businesses rarely have time to develop a long term strategy or even an orderly approach to the problem, expecting the process to be quick and easy. The third part of the problem is based on the previous two. The consultants hired to assist in the transition have no way to know where the next frog will leap, or what following any particular path will cost in the long run, or even necessarily how to identify the crucial factors in choosing one path over another.
This section of the manual is intended to identify places where the introduction of computers in your wood products business is likely to provide benefits that outweigh their costs, and proposes a method for incrementally developing a business-wide production information system.
Local area networks (LANs)
Local Area Networks allow multiple computers to exchange information at very high speed, using dedicated runs of inexpensive wire. There are several varieties of networks, including IBM's Token Ring, StarLAN, and AppleTALK, but by far the most popular small computer network is called Ethernet. Most Ethernet networks are put together to reduce the total investment in hardware & software, and other resources. Adding network software, an internal "Ethernet card" and the necessary wiring adds approximately $175 a "seat" to the cost of a business computer system, which is substantially less money than the cost of putting a printer (especially a good laser printer) on every desk. This allows files and printers to be shared. It also allows Electronic Mail (E-mail), Voice Mail and FAX systems to be routed through the company's computer wiring system.
The most popular Ethernet operating systems run in conjunction with MS-DOS, and most support Microsoft Windows. The Novell system is the most popular. Other popular systems include TCP/IP, LANtastic, Farrallon (for the MAC) and Windows for Workgroups. Choosing among these options is a critical decision that will be with you for a long time.
The idea of a workgroup fits directly into the focus on teams and teamwork as the basis of design. A workgroup is a small group of computers within an organization, tied together by both a continuous Ethernet cable and a common purpose.
The hierarchical structure runs as follows: the organization, the workgroups, the personnel. Workgroups usually contain less than twelve computers, even in big organizations. A computer can be a member of more than one workgroup. Workgroups are normally assembled around the resources they need to share, most often the information they exchange or the function they perform; either by Project (Product, Trade Show, etc. ) or by Function (Accounting, Production, Sales, R&D, etc.).
Within the workgroup, resources, including printers, hard drives and C-D ROM's are shared very efficiently. In the Windows for Workgroups metaphor, every disk drive in the workgroup can be accessed through the file manager on any machine. "Sharing" information in individual directories files is elective, subject to the permission granted by the authorized user of the computer (presumed to be the creator of those files). This permission (sharing) is active at the level of the sub-directory. Directories can be shared or not shared. If shared, they can be shared as read only or as full access. Passwords are elective: they can be required to access shared files, with a different password required for read-only than for full access, if desired.
File sharing substantially simplifies the operation of a business.
Modern software has been developed to provide additional features in a network environment, especially control of revisions
The network allows a designated individual to maintain the personal calendars kept on the machines within a workgroup and schedule activities such as meetings. Access to calendars also allows information to be collected from people's task managers to generate management reports.
Easy information access and exchange is potentially far more important to your business than the money it allows you to save on printers. But before you can begin to reap these benefits, you are required to invest a substantial amount of time and money in developing a "system" to handle information.
Estimates of the amount of time small businesses spend looking for "lost" information are difficult to substantiate, but in my own life it has always been more time than I can comfortably accept. Ten years ago, in the midst of a flurry of patent work, I watched my patent attorney use the intercom to dispatch his legal secretary for a file folder containing information pertinent to our discussion. She was back with the file before the discussion had moved away from the topic, and I was really impressed.
From this episode I extrapolated a principle: if you can put your finger on any piece of information that is within your area of expertise or responsibility in less than 5 minutes, you are worth over $100 per hour. The scale is very steep. If it takes you longer than 15 minutes, I probably can't afford to do business with you, because you are too poorly organized.
Computers were sold to us as nearly magical power tools which would help us clean up our messy desks. In fact, our messy desks and messy lives filled up our computers with messy files and most people have more trouble finding things in their computer than they do in their attic or garage.
In the early days of business computers (up until about 10 years ago: the days of business minicomputers named Prime, Data General, Unisys, VAX, IBM System-36, etc.), the organization of business information was imposed by the information systems manager (MIS). Data was entered into a database by clerical support personnel, and management reports (selective listings of that data programmed by MIS) were generated in response to a "query" and pushing special buttons. Form letters and billings were simply special reports, generated from data already in the database. Word-processing was carried out on dedicated machines (Wang, etc.) which could perform "mail merge" functions, sending personalized letters based on listings (reports) output by the minicomputer.
When personal computers (PC's) became sufficiently powerful to handle business applications, minicomputers began to lose their hold on the small business market, and in many organizations minis were replaced by individual PC's or small, clumsy networks of PC's, based on the advice of inexperienced "System Integrators" many of whom were really "Value Added Retailers" (VARs) who sold systems designed to assure themselves profit. The most important software tools at this point were relational databases, word-processors and spreadsheets. These programs gave individual users great power, but little guidance. The heavy hand of the MIS department was lifted, personal computers sprouted like mushrooms on peoples' desks and everyone was "empowered".
But almost no one had a clue how to use these tools. Spreadsheets were used to set up forms and then used like electric paper, and word-processors were used like typewriters. The standards for "finished" documents got higher and higher. A letter took more drafts to get it to look "perfect". Computers began to compete with copy machines as the most effective paper wasting devices since the Sunday newspaper. Everything took longer to do. This is when computers began to slow down the already slow to a crawl.
The swift did not simply turn employees loose with computers. They built very elaborate systems with very spare "user interfaces". Often, the only way to enter information was to fill in pre-defined data-entry "fields" in detailed, on-screen forms. These entry fields can be programmed to perform "error trapping" which refuses to allow the wrong sort of information to be entered. This does not preclude data entry errors, but at least addresses problems caused by spelling errors, and by getting numbers in a place where words (computer jargon for these words is "strings" or "text strings") belong. The user did not have the power to change or to direct the system. The goal was to get information in and work out.
There would be time for empowerment and Graphical User Interfaces (GUIs) after the system was running smoothly. Look at the computers at your bank. What do you see people using? Dedicated terminals and the wimpiest of old MAC's mostly, running on a network (LAN) linked to another network which connects branches to the main database located somewhere else. These computers are too small to run modern application software like Word or Quattro Pro. They are running software custom written to do specific tasks with the resources available.
One of the most important recent developments in software is the development of the virtual factory. The virtual factory offers several profound advantages over the traditional factory. In spite of the enormous cost of setting up a virtual factory, for a company the size of Boeing, Sony or Hewlett-Packard, it can reduce the cost of introducing a new product many times over. It can also speed the process of getting into production substantially, compared to using traditional methods to design and tool up for a new or revised product, and also leads to better, cheaper products.
It may be hard for you to imagine how this technology applies to small woodworking operation, but it will become clear soon.
I like to use a visual "virtual factory" metaphor when I think of manufacturing processes. I imagine a cartoon animation of the factory and a stream of material, slipping and writhing like a school of herring on a cannery ship, moving along the line. At every kink in the line, fish slosh off onto the floor. The cleanup wastes both time and fish.
Imagine your own operation in similar terms.
Since you actually build it, you can describe every step in the most minute detail. You should not think "drive screws into slide on left drawer side". Instead, you should actually see the operator reach up and pick out a screw from the screw-bin on his right, with his right hand, and pass it to his left hand and pick up the screw gun with his right hand, and fumble a little while he balances it on the bit, and then put the driver down while he repositions the slide on the drawer before he picks it back up to drive the screw into the drawer side.
All the while, you can't help but think about the new screw shooter you need to buy, and wonder if the one that feeds screws to the bit inside an air-hose or the one that uses screws on a reel is the better value, and how much faster either of them would let him be... how he could probably have installed two slides in the time he just spent putting in the first two screws.
This may be true, but look closer. Fumbling with the screws is not the only place where fish sloshed onto the floor in that movie. The analysis is easy. You can do it with or without a stopwatch.
How do you actually locate the slide?
Isn't there a way to use a jig to get the screw in the right place a bit faster than that?
Or some way to redesign the drawer so it automatically locates the slide?
How much does it cost to build the drawer?
(Guess, then look at the PDM and see if you are right.)
Be honest: make the cheapest, most cost effective changes first.
Applying the Design Process in a disciplined manner demands that you (and others in your organization, including the person shooting the screws into the drawer slides) look at all the parts of the drawer and list the function each serves, and look at all the steps that go into the manufacture of each of these parts and of the entire assembly and look for ways to integrate their functions with the operations that create them. In a perfect world, the pieces might actually hold each other together or locate one another. Maybe there is a cheaper way to address the entire drawer slide problem. Is there a new design on the market?
The shocking cost of doing things
Each fabrication step has a calculable cost. Eventually you will have costs in your operation defined with enough precision to allow you to evaluate the differences between a minute on the saw, a minute on the router table or a minute on the assembly bench. But for now, unless you have a lot of $20,000 machines, it is safe to assume that the primary cost of any operation is labor.
This is the realization that led directly to the development of self-adhesive sanding disks. Prior to 3-M's introduction of Stick-it disks, the cost of changing the paper on the sander was often greater than the cost of wearing it out.
The concept of "Earning Value" was introduced in the previous chapter. In the processes we have just observed, value was only earned while the slide was being positioned and attached to the drawer, a very small fraction of the total time the operator was occupied with the drawer. All of the other costs must be assigned to "overhead" or amortized over the production life of the product. These costs can be minimal or they can be enormous. In order to accurately set the price of an item, you must know what these costs are. In simple analysis, these factors (non value-earning operations, development costs and the creation of production tooling) define the difference between "Cost" and "Price" in your bids.
Obviously, if you are designing to a hard price established by market factors, the constraints on your design efforts will be defined by the price point you are designing to. The customer wants to see the greatest amount of "value" delivered at that price. You want to see the greatest rate of transformation from material to product per unit of time. Your employees want meaningful lives. Your investors (or your banker) want to see the promised return on investment in machinery and tooling. All these factors pull in different directions, and all have to balance somehow.
Use a computer to track costs. Begin collecting data and gradually develop a system to integrate it into one cohesive system.
Sources of readily available data:
Utilization of tools:
The profile that follows is a fictional company. Were it a real company, it would be potentially viable in the short term, but it has many operational problems. Manufacturers are usually too stretched to get a new product fully "designed" before they find themselves in production, and small manufacturers rarely have time to redesign a product once it is in production. Sometimes, only the threat of disaster can provide the impetus for change.
We will begin by looking at the operation, then we will use it as a model. For the sake of illustration, the fictional company was faced with a major setback and responded by increasing its efficiency entity-wide.
The net result is an increase in stability and in bottom line profitability through more efficient use of computers, the introduction of project management tools, and through substantial revisions to work-flow and application of out-outsourced CNC work for some parts previously fabricated in-house. The result of this experience with computers and CNC will drive a complete re-think of the company's business over the next 2 - 3 years.
The Alderberry Group custom-builds cabinets for homes, offices and retail stores, and manufactures mid-priced, ready-to-assemble (RTA) computer furniture in a 6,300 sq. ft. factory in Sequim, Washington. Alderberry began 9 years ago as a custom cabinet shop and gradually moved into contract sales through mail-order distributors. As the mail-order business grew, machinery in the custom shop provided most of the manufacturing capacity. Over the past 2 years, more specialized machinery has been installed, financed by owner investment (borrowing) recaptured through overhead charged against the revenues from the RTA lines.
100% of their "all wood" RTA furniture is marketed through a national direct mail channel. This line is marketed through RainBarrel, a Chicago-based direct-mail catalogue which carries a mix of garden tools, sturdy clothing, solution-oriented household items and home / home-office furnishings. Alderberry is in its second year of contracting to RainBarrel.
Products sold through this channel include four modular units made from 100% post-industrial scrap materials: solid hardwood panels made from finger and edge-jointed mill-ends. These modules can be combined to create a range of workstations suitable for small offices or home offices. Much of the material sold through this catalogue is manufactured offshore. Conspicuously absent from the catalogue's descriptive prose is any discussion of the work-place environment in which the products are produced.
The RTA suite is sold as individual modules and produced on order. Alderberry drop-ships directly to the end-user out of the regional UPS facility located at the Port Angeles Airport, 14 miles to the west.
All of RainBarrel's catalogue items are made from environment-friendly materials,..."from sustainable plantation forests, recycled glass, wool; leather and cotton." The catalogue is targeted at aging baby boomers: productive middle-agers 35 - 50 years old. These are two career households with four people per house. The catalogue claims a mailing list with a median family annual income over $65K. Alderberry is more interested in the activities of its customers than their income.
Statistical information collected from RainBarrel indicates that most orders were faxed and RainBarrel's analysis of the orders indicates that over 60% of their customers have fax machines at their homes, using the same line as their home phone number. This information implies that they maintain home offices and are therefore candidates for Alderberry's offerings.
In order to be accepted into the RainBarrel Catalog, products must meet a range of criteria, including conspicuous use of recycled materials. Key selling features of the product line are its elegant design, based on unique, solid wood construction, and the recycled materials used in the modules. The Alder panels are not stained and the resulting units are light in color. All parts are machined to provide aesthetically pleasing rounded corners. Fasteners are used decoratively and covered with rounded wooden plugs. Ingenious connectors allow individual modules to be integrated into larger structures. Alderberry Group's products are "Crafted" to provide the feel of enduring quality. Detail and finish are deliberately reminiscent of the Skaneateles (rock maple) train sets target customers played with in their youth. Large panels are branded with a woodburning iron. The brand resembles an engineer's seal, with symbolic recycling arrows and states "Made from 100% recycled materials from sustained yield forests". Finished goods are also branded "Grown and manufactured in the Pacific Northwest".
Once you have your foot in the door, and are qualified to be purchased, you still face competition before the purchaser places an order. The most critical "order winning" criteria are price and quality.
Alderberry has quality under control. (In fact, quality is probably too high for the target market.) As a result, they are not entirely price competitive with similar offerings made in Finland and Phoenix. Alderberry is convinced that a second set of criteria can be used to pull their customers up to the slightly higher price-point: "ethics".
Alderberry relies on the "green" tendencies of their target customers. RainBarrel's mailing list is based on contributor's lists from many of the national environmental organizations, and Alderberry is relying on these organizations to maintain a high profile for the Northwest's timber crisis, the continuing plight of displaced wood products workers, and the need to provide meaningful jobs.
Alderberry's ad copy "personalizes" the manufacture of their products and offers the jobs they provide as solutions to this problem. Photos show their workers (implied to be displaced timber workers) fitting parts together.
Each product or line (custom shop, RTA product) is run as an independent cost-center, allowing accurate assessment of the profitability of each operation. Non-production overhead is allocated to each cost-center on the basis of labor hours and machine time.
Custom line: $380,000 sales in 1994
Custom work in the area is limited. There is considerable competition, including devastating competition from "low-ballers" who seem intent on driving other companies out of business, bidding very low, but leaving out critical parts of the design specification in their bids, thereby requiring numerous change-orders and contract additions which ultimately drive their price far beyond even the highest bidder's price. Analysis of time sheets and financial information indicates that the Custom shop is substantially less profitable than the RTA product lines. Alderberry has found that the "hassle-factors", the cost of closing sales, the associated cost of estimating, the costs of initial bidding and negotiating work change orders (WCO's), and installation costs are substantial and exceed what can reasonably be charged for them.
RTA line: $720,000 sales in 1994
Parts (except for metal brackets and fasteners) are produced in-house and production is still based on traditional tooling (saws, shapers and routers).
No CNC manufacturing capability is available within a reasonable distance and the cost of coordination, communication, packaging and transportation appear to keep out-source production of individual wooden parts slightly less profitable than in-house production.
Several stages of finishing operations are required to produce this line, including sealing, coating and polishing. The cost of these finish operations is very high. Space is precious and finished goods require careful handling and a lot of rework.
Environmental regulations and OSHA concerns have continued to drive the cost of compliance with air quality standards higher and higher. These concerns led to a decision to out-source all finish operations. However, Alderberry has been unable to locate a competent and reliable outsource finishing operation, and has been forced to recognize that no outsource finish facility is available locally.
Last year, these operations were performed in-house. Volume demand has forced the space once occupied by the finish shop to be devoted to shipping and receiving. Currently, cases are transported to the autobody shop 13 blocks away and sprayed there. A special trailer was constructed to move material between Alderberry and the paint shop, which also holds batches of doors, drawer-fronts, and case-goods during transportation and while they are sprayed.
The capacity of the paintshop is low. Scheduling (especially when weather is bad) is problematic and much time is wasted loading and unloading the trailer. This solution is understood by all parties to be strictly short-term.
It is a bright Monday morning in early June. Alderberry's sales manager has suddenly encountered an enormous manufacturing problem:
His top customer (RainBarrel) has just been purchased by a larger company. The new owner plans to open 22 retail stores during 1995 and needs floor goods and inventory for these stores. Their buyer, with whom Alderberry has worked closely for over 2 years, has given him until next Friday at 4:00 p.m. EST to provide revised prices and delivery dates or his new boss will begin an aggressive search for a new supplier.
Alderberry's sales manager already knows that the requested shipment dates and the volume requested substantially exceed his company's manufacturing capacity, and that the terms of these sales cannot justify the expansion necessary to produce these items at the requested rat and at the requested price the way they are building them today.
He calls you (the owner). What are we to do? Can a redesign of the product or of Alderberry's manufacturing operation, and maybe the addition of a few strategic pieces of new equipment increase throughput in the current facility? You already know where the production bottlenecks are.
Can we train and recruit people to add a second shift? Can you find some other manufacturers in the area who already have the needed equipment and have excess production capacity? Can distributed manufacturing turn this apparent catastrophe into a great opportunity? He needs an answer right away.
What do you need to know to answer these questions?
RainBarrel has raised two concerns: cost and volume. As a businessman, you can see his point. The increase in volume (about 166% averaged over the year, but a 290% increase for the next 2 months) ought to justify the reduction in unit cost (15%) he is looking for. However, that 15% is close to your total remaining margin on these items (after finance charges on the equipment you bought this year are figured in).
You scratch your head for a while and then realize you're getting nowhere. You decide that you must address the problems independently.
The "unnecessary" cost factors: how many can be reduced?
Eliminate the need for unnecessary operations
Until you break down the actual cost of production into sufficient detail that the true cost of all operations is apparent, it is very difficult to realistically evaluate the relative benefits of available options. The process of reducing total parts count and total operations is generally called integration.
The opposite of integrated construction is modular construction. Generally, designs become more integrated over time.
Modular design trade-offs
Eliminate inefficient resource scheduling
One of the tests of production scheduling is whether or not the demand on resources is generally stable or experiences unacceptable peaks. The peaks result from inefficient scheduling, often due to uncalibrated performance expectations. Consequences of the peak demand and scheduling conflicts cause ripples of inefficiency to resonate through the operation. One of the reasons to develop and maintain the PDM and to explore implementation of Project Management software is to allow the timing of demands on resources to be coordinated. This is usually far less expensive than increasing workforce, floor space, or machinery.
Eliminate part(s) through integration
In the case of Alderberry's desk, we have an option to turn the side subassembly, a 4 part unit requiring 26 machine tool operations, into a 2-part unit requiring only 16 operations. The economics of this decision are not simple: The 4 part unit uses 20% less material and weighs 20% less, reducing both material requirements and shipping cost. What other options could reduce machine time for this item without increasing shipping weight and material requirements?
Reduce cost to maintain inventory
A balancing act between running out of material and paying for storage and financing inventories.
Reduce non-value earning activity
Once you start watching the ratio of value earning activity to non value earning activity in your own operation and see how little of the time your payroll buys is actually spent converting materials into products (compared to simply moving material from place to place or preparing material for its transformation), you will recognize that the greatest potential to increase profitability is by converting this lost time (which you are currently paying as much for as you pay for any other time) into value earning activity.
Alderberry's manufacturing facility is not yet well-organized. Material and work in progress are handled repeatedly. There is not yet a smooth and steady movement of material through the plant.
In a large operation, the lost time constitutes a major gold-mine. Harvesting and harnessing this stream of money, and reinvesting it into increased efficiency and increased productivity, is the goal of management. In the Japanese model, everyone in the operation is recruited into the quest to increase quality without reducing efficiency. This is accomplished by the gradual and continuous eliminating of opportunities for defects to occur.
Reduce cost to set up for each operation
Traditionally, installation of specialized machinery and hard tooling have been used to minimize the repeated expenses of setup and startup. However, modern Flexible Manufacturing Systems (FMS) offer great advantages over dedicated machinery, often at competitive cost. The cost of this equipment is dropping rapidly and is already proving highly cost effective for operations ready to take advantage of the increased productivity it can provide.
Alderberry has already made substantial investment in flexible tooling by creating CAD drawings for all the tools they use to router-cut parts, and management has recognized that the cost of contracting pre-cut panels could be more than merely competitive with fabrication of the same items in-house (if scheduling problems could be overcome and the parts were designed for this type of manufacture). Currently, many parts require multiple router operations to create the joints that connect corners to panels. These connections, or the tooling used to fabricate them, would have to be completely re-designed before out-outsourced CNC panel cutting is truly cost-effective.
The primary obstacle to the purchase and installation of CNC equipment is the impact on staff and overall plant operation. Current volume of production could not justify or pay off a complete redesign / retool to take advantage of the new technology. Furthermore, in this product line the primary production bottle-neck is in the finish operations, not the panel cutting shop.
Crafters are generally afraid of the impact of this technology. None have begun training to become CAD or CNC operators. Also, in-house production provides "levelizing" work for Alderberry's employees. Scheduling allows machines and employees to work more continuously. There is some concern among employees, in spite of the personalization of employees in the catalogs, that the owner's fascination with new technology will lead him to purchase CNC capability in-house and that some of them will be displaced.
All furniture is sold finish sanded, but entirely unfinished. This substantially reduces production cost by eliminating the need to provide finishing or drying facilities. This simplifies heating and improves air quality by eliminating the need to handle Volatile Organic Compounds (VOC's) in the work-place.
All patterns used in redesign of this line are generated in CAD and were cut using a CNC router. This allows close tolerance fits, moving tooling from shop to shop, and quick replacement in the event a pattern is damaged.
Overview of this operation
Alderberry makes five basic modules which comprise their home office corner suite. These include: the central workstation desk, the return wing, the corner-monitor support, the monitor surround / hutch, and the 2-drawer rolling file cabinet (which fits under either the computer workstation desk or the return).
Typical installations range from simply the desk & keyboard support to complete "office suites" including multiples of all pieces (plus at least one additional file cabinet).
Each section is batch-produced in the shortest economical runs, which range between 4 and 8 units, depending on the piece. The actual size of each run was determined by evaluating four factors:
List of items produced
List of parts in each item produced
Optional Keyboard Tray is a sliding frame (very different from stationary tray in the winning entry) which mounts under the desktop. It is made from 5 "rails" and a bottom. The design provides wrist support and a built-in copy-stand function, as well as providing Pendaflex "hot file" storage in the wasted space forward of the operator's knees (between keyboard and CPU / Monitor). This design allows the mouse pad be located on either the left or right side of the keyboard.
Keyboard tray is composed of:
The hutch / surround straddles the monitor, providing additional above-desk storage. The hutch is composed of 3 sections: two side sections and the top.
Monitor corner support
The monitor support fills the space between the back of the desk and the corner of the room, and supports oversize monitors which otherwise hang unsupported over the back of the desk. It reduces the size of panel required to construct desk-top and reduces the package size, thereby reducing shipping cost of most units. The monitor support is composed of 4 sections:
Define tasks: List each separate material handling step for each part identified above
Developing an inclusive list of steps and assigning task (tools) times and dimensions to these items is essential to accurate cost control. It was provided as an "out-of-class" homework assignment. Typical part fabrication scenarios are provided below as examples of detail required in a PDM:
The Keyboard tray is composed of 5 edge-joined "rails" and an inset plywood bottom. The rails are based on 2 custom fabricated sections shaped from finger-jointed hardwood millwork. Pendaflex file supports and the slot for the bottom are integral to one of the millwork sections. The other section, which is larger, provides a groove for the bottom slot which is used for the front and the left and right ends. The unit is assembled (glued) around the plywood bottom and finish sanded after assembly.
Metal slides are used which allow up-down adjustment.
Define setup of individual workstations
In manufacturing circles, CAD usually means Computer Aided Design. Corporations like Boeing, General Motors and Sony use Computer Aided Design software as the backbone of their product development systems.
Virtually the entire Ford Taurus was developed inside one software package. These CAD packages run on powerful networked workstations and are used to generate photo-realistic renderings and to drive the CNC mills that carved out production tooling like the solid steel injection-molds for the car's padded dashboard.
Computer Aided Design systems are also known as "High-End
In the secondary wood products industry, CAD typically means Computer Assisted Drafting. There is an enormous difference between the capabilities and the costs of these systems. In spite of the fact that what we all wish we had is Computer Aided Design, or "High-End CAD", the focus of this discussion is on use of the "low-end" drafting variety of CAD System.
The performance lag between high- and low-end CAD is presently about 10 years. This means that the most powerful low-end software offers performance approximately comparable to the high-end systems of 1985. This performance is not to be sneered at. The difference in cost is close to 2 orders of magnitude. Capability that cost over $500,000 in 1986 now costs under $5000 and is much easier to use.
Design of products in CAD
"Easier to use" is clearly relative: At this point in its development, CAD is still an awkward solution to getting information into the computer. It is much more difficult and expensive to generate a cut list for a cabinet or a set of drawings in a CAD program than it is to produce them with a spreadsheet and traditional drafting tools. However, once the information is entered into the machine and corrected and documented and saved in a file and safely backed up, it is as easy to get it out of the machine as it is to get this document out of the printer. And when revisions are needed, it is as easy to revise as a word processing file.
Even low-end CAD is computationally intensive, so it needs fast computers Moreover, it is still expensive. AutoCAD, the industry standard in low-end CAD, costs about $2800 and it takes most people a few weeks of training and at least a year of experience to get reasonably good at running it.
History of all revisions
What low-end CAD provides is a way to organize information, generate drawings, maintain standard libraries of shapes and other details, and track revisions. Drawings are important, but even more important are the drawing files AutoCAD creates. Other software (drivers or post-processors) translate these drawing files into sets of instructions that drive Plotters. Plotters push pen nibs across the paper in sweeping arcs or tight circles. The levels of precision are measured in thousandths of an inch.
Control of machine tools
Tools besides plotters can be controlled by these files. The advantage of AutoCAD over other low end systems is that there is so much third party support for it. Third party support means that companies other than Autodesk have written software that loads into AutoCAD and increases its capabilities, providing features that tailor it to the needs of specific industries, like yours.
Rumor Mill: RouterSIM software is not really available yet, but it is scheduled to be demoed in this course. For another $6500 you can buy RouterSIM.
RouterSIM is an add-in program which allows AutoCAD to drive CNC routers directly. It uses AutoCAD's ADE (AutoCAD Data Extension) or other external databases to maintain libraries of cuts, material characteristics, etc, including all the information you accumulate "proofing" the cutter path.
The specific post-processor which actually generates the G Codes and M Codes which control a particular CNC router costs another $1000. This means that for under $10,000 in software, you can purchase computerized wood-working power that may well exceed what the $500,000 systems offered as little as two years ago.
Library of patterns
Standard details provide a step toward interchangeable information. More and more suppliers are providing precise, accurate detail drawings of their hardware, fasteners, etc., in the form of AutoCAD files. You can load them directly into your design, thereby assuring that things will fit as planned.
Material requirements planning (MRP)
MRP is a set of techniques that uses bill of materials inventory data and the master production schedule to calculate requirements for materials.
- American Production and Inventory Control Society definition (APICS)
MRP is a "push" based system.
A process from industry scaled down for small operations: