Happy’s Essential Skills: CIM and Automation Planning, Part 2—Six Principles of Automation
In Part 1 of this column, I discussed the foundation of CIM and the principles of automation planning. In Part 2, we will assume that all the necessary preparations in strategy and tactics have been completed. How does it all fit together for successful implementation? This problem affects large, wealthy companies as well as the smallest job shop.
I would suggest that successful implementation of automation depends on close adherence to some cardinal principles. Six are reviewed here:
Superiority: automation must contribute to business goals
That business goal in simplest terms is being the best. But "best" is a relative term, so how would you rate yourself? Would it be on experience, reputation, technology, profitability, service, and engineering? How would you compare yourself to your competitors? What do your customers think is important in rating "BEST"; Quality, Delivery, Price, Flexibility, Technology, Service? The selection of which area of performance that automation is aimed at will have the most influence on picking vendors and programs.
The '20−40−40 Rule'
In a recent publication about Computer Integrated Manufacturing (CIM), Wickham Skinner quoted the General Electric '20−40−40 Rule'. This says that in typical fabrication and assembly production plant only 20% of any ultimate cost saving and performance improvements come from productivity changes and conventional engineering concepts and techniques. Whereas, 40% can come from manufacturing policy and structure changes (TQC, LEAN) and 40% from improvements in fundamental manufacturing technology.
This gives a clear alternative to smaller companies who can't afford expensive automated equipment. Their management can make a much more affordable investment in "Policy and Structure Changes." This is just another way of saying 'manufacturing philosophies'. As mentioned earlier, the important ingredient is commitment to be the best. Once this commitment has been made, then can come the investment in education, awareness, and training.
Simplicity: automation must help simplify manufacturing
It is imperative to use the technology of automation to simplify the production task rather than make it more complex. Part of simplifying the problem is not automating at all any operation that is better done by human skills. The basis for this principle is that automation is consistent, untiring, and fast, but unlike humans, it is not possessed with common sense and the ability to change its own programming when a glitch appears. To take advantage of automation then, we have to simplify all the factors from the previous manual technique.
Total Quality Control (TQC)
Total Quality Control (TQC) is the foundation of any excellence program. It is a management and operating philosophy totally committed to quality that focuses on continuous process improvements using data and the scientific method making perfection a goal. It requires universal participation by everyone everywhere, working as a team, so that the result is customer satisfaction, where expectations are consistently exceeded for both internal and external customers.
The vital elements of the TQC process are clearly-understood and agreed-upon goals; appropriate performance measures; rigorous information collection and qualitative as well as quantitative analysis; an approach utilizing creative problem solving and first and foremost, participation by all members using teamwork. This entire process must be driven by top management.
The working process of TQC is to fix the process and make it work better. All activities are processes, so the TQC methodology starts with a four-step procedure:
- Identify the problem
- Identify the causes
- Eliminate the causes
- Monitor the process
Although this may seem simple, it is—but only after everyone involved—workers, supervisors, engineers, and managers have received training on the elements of TQC. Management must back this training, from providing the initial instructions all the way to statistics experimentation, to time for employees to learn to use these skills, but primarily in reinforcing that commitment to be the best.
So why has TQC taken so long to be accepted? The answer may be that TQC is anti-intuitive in our business culture. For instance:
If we don't trust a vendor’s performance ...
WE ADD ANOTHER VENDOR!
If we don't trust our capacity...
WE ADD LEAD TIME!
If we don't trust our inventory levels ...
WE ADD MORE INVENTORY!
If we don't trust our quality...
WE ADD REWORK STATIONS!
If we don't have time to do something right...
WE ADD MORE TIME TO DO IT OVER!
In other words, our business culture causes us to react to uncertainty by adding complexity.
In fact, our reward systems encourage complexity. Gaining control over, and reducing complexity through knowledge and understanding are the primary objectives of TQC. One major task of automation is to simplify and organize complexity. A simpler process has:
- Less inventory
- Less floor spaces
- Less people
- Less process steps
- Less part numbers
- Less options, accessories, manuals, literatures, paperwork
- Less chance for error per unit of output
One role the computers of automation play in TQC is the collection, reduction and analysis of information and data. When a problem has been solved, the systemization role of automation constantly monitors to keep it under control.
Standardization is another method of simplification. Many times that is why you will see companies standardizing panel sizes in production. What they may lose in material cost they can make up in improved performance from a simpler automated process. Other candidates for standardization is image transfer, and NC tooling, procedures, equipment, and especially training. Even such obscure tasks as costing and accounting can benefit from standardization. But let me say it one more time: Automation will require simplification.
Flexibility: automation must adapt to changes without repeating the initial investment
Trends in Automation
Historically, if the manufacturing environment was simple enough, the product quantity large enough, and the product characteristics stable enough, you would invest in fixed or rigid mechanization. The only other option was to leave it essentially manual. This applied equally to a single task or an entire manufacturing sequence. Recently, as we talk and view automated systems, the trend is toward flexible and adaptable systems. While labor and fixed automation is increasing in costs, newer technologies are bringing flexible systems down in cost. Viewed as a 'per unit cost,' this means that the intersection of flexible systems versus manual or fixed systems is spreading. This spread covers the typical volumes seen in batch printed circuit production.
Flexible automation in printed circuits today is typically programmable and computer-aided based computer numerical control (CNC) and direct numerical control (DNC) of shearing, drilling, contouring and photo-plotting are examples, as well as computer-aided inspection (AOI), computer-aided test and process automation, and computer-aided artwork/tooling (CAM). Direct imaging and inkjet printing are examples of flexible automation that eliminate many human/machine steps. All these techniques are truly automation as we have defined it, since they have both a mechanization and a systemization content.
Modern Information Systems (MRPIII)
Flexible automation that is mostly systemization would be the role of a modern information system. For production processes that technique is called manufacturing resources planning (MRPII). This, and the older materials requirements planning (MRPII)—is a management process or technique for taking the business plan and breaking it down into tasks of materials, inventory, schedules, and costs. Specifically, the detailed tasks include:
- Business planning
- Production planning
- Order processing
- Master scheduling
- Materials planning
- Shop floor control
- Vendor scheduling
- Planned execution and feedback
There is capability of doing evaluations and "what if" scenarios. MRP is a powerful discipline and philosophy, but it is based on company-wide teamwork and detailed implementation—again driven by top management.
MRPIII can be used in just about any size company making any type of product on a process or batch order flow. Some companies using MRP employ as few as 50 people and have annual sales as little as $3 million US. The four basic MRP packages (Figure 7) for discreet product manufacturing are:
- Traditional MRP with varied routings
- Material based backward scheduling
- Individual shop orders
Disconnected batch flow:
- Lot control
- Serial number BOM effectiveness
- 7000.1 cost accounting compliance
- Fixed routing cumulative MRP
- Backflush inventory
- Daily or weekly schedules
- Capacity based forward scheduling
Figure 7: The information extent of systemization varies with the type of manufacturing.
MRPIII systems will not become obsolete by CIM or automation. In fact, just the opposite, as manufacturing systems become more dependent on systemization to control the mechanization, the manufacturing planning and control function will be more indispensable. As we have seen, ten years ago MRP was essential for:
- Material requirements planning
- Capacity requirements planning
- Order entry, master production scheduling, shop floor control, forecasting, resources requirements planning, purchasing distribution resource planning, and cost accounting
Today, MRPIII has added:
- Group technology, preventive maintenance, simulation through-put optimization, demand-pull interfaces, manufacturing decision support, production documentation and computer drawing graphics interfaces.
MRPIII, then, is a technique that centers on the fundamentals of materials and production planning and control. It stresses very accurate data that increases visibility into manufacturing. MRPIII provides a common language for communication—a company game plan that calls for company-wide teamwork and discipline to make it work. It is a basic, comprehensive approach to running a manufacturing operation. There are a large number of MRPIII general purpose systems available today, at a very reasonable cost. There are also two or three MRPIII systems designed specifically for printed circuit fabrication.
Consideration of Advanced Technologies
The remaining 40% of potential performance improvement is contributed by advanced manufacturing technology. In applying the principle of flexibility to new equipment, processes, or materials, one should design the automated system to handle a wide variety of operations, not just one or two. And part of making it flexible is building into its requirements the capability of adding on new technology or replacing parts of the system with new technology as it becomes available. That will require being on top of trends and developments to such an extent that as we design the system for today's needs, we are also working on the needs of tomorrow.
I believe these advanced technologies come into use as part of a "wave theory." That is, the new technology is first picked up by a small group of "initiators," the risk takers, who may be 2−5% of the industry. By the second to the fourth year of this technology, the companies with reputations of being "progressive" have assimilated this technology into their operations. This group numbers 15−18% of the industry. The remaining 80% of the industry will integrate this technology over the next five to 14 years. By this time, if it is still viable, it will be common practice and knowledge. Remember, the printed circuit complexity factor will increase by 10x every 13 years. This is one of the driving forces behind the technology turnover and is a major consideration in the automation planning cycle. By checking how many years a technology has been out, you can place yourself with respect to the “waves,” and use this as part of your technology acquisition targets.
Compatibility: the coexistence of automation and manual techniques
One of the simple truths in automation is "If you can't do it manually, what makes you think you will do it by automation," and the corollary, "automate for quality" is a myth. Automate for consistency, either consistent quality or consistent scrap. The automated system must share the same heritage as the manual systems. The most suitable manual technique for automation is Lean (JIT) or the continuous pull production technique. It focuses on many of the following problems in a conventional material flow system:
- Excess inventories queue and safety buffer
- Extensive repair and rework
Lean (synchronized) manufacturing is a logistics approach designed to result in minimum inventory by having material arrive at each operation just in time to be used.
Orders in a Lean system are pulled through the system by demand. They are often triggered by a reorder point system called "kanban." Every time a container of parts or materials is issued, the item is immediately ordered.
Lean applies to job shop, batch, and assembly line manufacturing but is most common in high volume, repetitive processes where a common product is being manufactured. The Lean approach reduces inventory or buffers of all types to a point where it cannot hide problems like unsuitable materials, late deliveries, or inconsistent processes. LEAN forces a business to stop the line and fix the problem before rework is created. LEAN implies changing the physical process and plant layout to reduce transit time and therefore cost and buffers. Again this shares a common philosophy with Grouped Flow Manufacturing Cells and TQC. TQC must exist within any business considering implementing LEAN. The TQC methodology must be applied everywhere by top management, even to developing a strong supplier relationship and maintenance program.
The payback of a TQC/LEAN program are real savings in dollars! Higher quality is achieved, lower inventories, work-in- process inventory tracking is no longer essential, space is reduced, equipment utilization is higher, and labor cost of all types (direct and indirect) is lower.
An automation methodology is a formal procedure for planning, designing, and implementing automation. It is particularly important when you want to start integrating several previously independent production tasks into one or more automated systems. The methodology stems from the previously defined Automation Matrix (Figure 6). Additional axes are added to the matrix to cover material handling (mechanization) between cells or work centers and to cover network communication (systemization) between cells or work centers. A simplified diagram is illustrated in Figure 8. The actual methodology will take up several drawing and utilize a number of worksheets to analyze and plan the data.
This methodology was used to design the automated printed circuit facilities for Hewlett-Packard in Sunnyvale, Palo Alto, Loveland, Boise, Boeblingen and Puerto Rico. The Automation (CIM) Information Flow Diagram from the referenced paper is shown in Figure 9. The complexity of the automation was enormously simplified by this methodology.
Figure 8: The Automation Methodology consists of automation plans for each WorkCentre plus plans for material flow and information flow between work centers.
Figure 9: The Automation Information Flow Diagram shows the major items of information transferred between customers and the internal work centers of modern printed circuit manufacturing.
Manufacturability: automation supported by product evolution
The majority of printed circuit boards are not designed by the one who fabricates them. It is very difficult then to change the design of a printed circuit. The feedback to the designers of printed circuits can then take one or more of these three common responses to the design:
- A printed circuit unsuited to the automated systems of the fabricator will usually have quoted a higher price than ones ideally suited. This has the tendency to send the buyer elsewhere, therefore selecting the products the automated systems will handle.
- Computer-aided tooling/artwork systems are used to process/methodize PC artwork files, put them on grid, clean up line spacing and straightness, align layers, standardize tooling and provides NC and AOI programs. They also can design the multiple image panels. All of these tasks are changing and improving the product. The printed circuit and its panel are evolving, all of which will improve the performance of the automated system.
- Design for Manufacturing programs can be undertaken by customer or product engineering. These programs all seek to have the customer do a better job in designing the product or making changes or edits that somehow will improve the product and make corresponding cost savings.
Design for Manufacturability & Assembly (DFM/A)
Design for manufacturability and assembly is a relatively recent engineering philosophy focused on improving the fabrication of parts or simplifying the assembly of products by analyzing value, tolerance, movements, difficulty, or suitability for automation. The approach can take many avenues but the goal is the same—simplify the product and make it easier to manufacture. One technique, developed by Professors Dewhurst and Boothroyd, and further refined by Hitachi and General Electric, calls for DFM/A to be based on a rigorous analysis of assembly part count, the complexity of motion and parts, and its assembly time. With this numerical rating, a more rational program of improvements is possible. See my column from June 29, 2016 for more details.
Other times, the program is implemented by the customer or product engineering. It is their job to supply customers with PCB education seminars, with design/cost guidelines and tradeoff comparisons. If producing the prototypes, then a manufacturability audit or recommendations are in order. By whatever means, the goal is to have a printed circuit more producible. In our earlier comments, this will have the effect of lowering the complexity factor (C). In fact, if automation is going to be utilized, this product evolution is essential.
There are other facets of the philosophy, group technology for one, as well as value engineering, tolerance and margin analysis, analytical trouble-shooting and design of experiments. Like TQC, MRPIII and GT, DFM depends on accurate data and analysis. Again, it is the information that is important.
Reliability: robust and tolerant automation for high functioning under adverse conditions
Automation will usually entail a sizable investment. If so, the return on this investment is most assuredly based on continuous use. In-operability due to breakdown, spare parts, operator mistakes or undue complexity cannot be tolerated. Primadonna systems are for research labs. A manufacturing system must be robust, easy to maintain and service, straightforward to operate, with a track record that speaks for itself.
Processes and Raw Materials Consistency
Process and material characterization is a major factor in the reliability of a process. The latitude a processes exhibits to variability in conditions and materials, are the chief factors in process control, quality and yields. This is the main focus of manufacturing philosophies such at statistical quality control (SQC) or statistical process control (SPC).
The SQC approach is essential to provide process reliability and meet a TQC approach. There are numerous sources of variability: materials, machines, tooling, workmanship, etc., and they all combine like tolerance. That is, they are not simple summations. The end result can be large and unpredictable rejects and defects, or if managed, they can be small and predictable.
To reduce process variability will mean working on machine instability, maintenance and calibration, improving tooling accuracy and ease of use, making set-ups reproducible and easy to adjust or have no need for adjustments, and making sure raw materials are properly specified and vendors have their processes under statistical control. Especially, it will mean training, coaching and well-documented procedures.
Leadership to Execute the Strategies
Automation, although highly desirable, is more than just buying equipment and processes from vendors. A successful automation program requires the focus of the business needs of a company. The first step is in fact not purchases, but commitment to being the best. Automation is not the start of this process; it follows other manufacturing programs. Automated manufacturing (or CIM) fits with TQC, LEAN, DFM, SQC, CAT/A, and FMS programs. Improved performance is achieved by these programs moving your manufacturing response curve (Figure 10) to the right, while customer improvement programs move your products (the PCBS) to the left. As the example in Figure 10 shows: a mediocre PCB at point 1 can be improved to point 2 or point 2’ by process improvement or product simplification, or better still, both will move it to point 3. This is the simple secret to the enormous success in manufacturing of the Japanese.
Figure 10: Improvement in yield and customer satisfaction is a combination of process improvements (2’ to 2) and product improvements (1 to 2) resulting in a markedly improved yield (1 to 3).
The management challenge is to:
- Think strategically
- Examine the role of technologies
- Use manufacturing and engineering philosophies to support the company's business goals
- Support ongoing programs of education and training in new techniques.
The keys to success in automation include seven checkpoints:
- Believe it can be justified. Lots of benefits will come from entirely unexpected sources.
- Recognize that enthusiasm, along with a champion, will work wonders.
- Start with a vison, but begin implementation before total detailed planning is complete. Early success builds momentum.
- Realize that your functional organization will try to get in the way. Don't let it happen!
- Get rid of a lot of obsolete traditions; they have no place in today's competitive environment.
- Rigorously apply TQC, or equivalent, before proceeding. Understand that technology is only part of the answer.
- Lots of benefits will come from simple improvements. Success comes from people not machines.
These seven ideas, along with the strategies, tactics, philosophies and principles outlined here, are all aspects of a commitment to being the best.
- CIM definition by CASA/SME.
- Wikipedia Definition-Computer-integrated manufacturing, https://en.wikipedia.org/wiki/Computer-integrated_manufacturing
- Holden, H.T., "Complexity Factor C", IPC Technical Review, March/April 1986.
- Wu, Bevan P.F., "Manufacturing Strategy Towards Integrated Automation," Taiwan Productivity Center Conference., December, 1983.
- Skinner, Wickham, "Re-inventing the factory," Harvard Business Review.
- Part 1 of 14 for DoD 7000.14-R, "DoD Financial Management Regulation," volumes 1 and 4.
- O'Connor, James F., "Making MRP Work in a Multi-plant Environment," PCFAB, September, 1985.
- "Case Study of PCB C.I.M. Fab Implementation," InterNepcon, Singapore, August 26, 1986.
- Boothroyd, G. and Dewhurst, P, "Design for Assembly," Dept. of Mechanical Engineering, University of Massachusetts, Amherst, 1983.
- Happy’s Essential Skills: Design for Manufacturing and Assembly, Part 1
- Wallskog, Alan G., "Meet the challenge of international competition for PCBs through strategic quality planning," IPC Technical Review.