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SUBJECT: Product Change Control

ALPHANUMERIC IDENTIFIER: Supplied by Instructor (leave space for)

BRIEF DESCRIPTION: Often overlooked, product change control is a key part of successful manufacturing organizations. The following highlights the five key principles of effective product change control in a global manufacturing organization.

KEYWORDS: Product Change Control, Engineering Change Order.

OVERVIEW:

Problems with product change control can lie at the core of many manufacturing problems – from quality to cost to on-time delivery. Additionally, since product change control affects virtually all parts of the manufacturing organization – including engineering, manufacturing, routings, machine setups, tools, the parts & service system, and even suppliers – it can have a wide spread effect on the organization. This section discusses four basic principles of efficient and sustainable product change control.

Principle # 1 - Avoid Unnecessary Product Changes

Product development is an iterative process and will therefore always experience some amount of change, however as shown above many changes are unnecessary and could be avoided if the engineer responsible spends more time on the first release of the component. Additionally, many changes are aimed at correcting mistakes made during previous changes because of insufficient information about the customer requirements.

• Suggestion - Use a common decision process for all product changes. There are two advantages to doing this. First, it ensures one consistent decision process for all changes and allows a common measure of the change importance so that the most critical changes get worked most urgently. Second, by centralizing the decision process efforts to improve the process can be more effective and less costly than trying to improve several decision processes.

Principle #2 - Improve Control of the Product Change System

Product change is centralized when the organization has only one standardized process and then each program uses that same process. There is a plan that defines the requirements of that process and a process manager who is responsible for the plan and the process and assuring that it fulfills the needs of all activities. Product change is decentralized when each program is allowed to establish its own version of the process. Although an organization may have a standardized template, an individual manager may or may not chose to use that template when they are challenged to do whatever it takes to achieve the business plan.

Many organizations have a standardized process and a process manager, however implementation is controlled by multiple plants and central change control groups. These groups each have their own business plan and manager. The managers are responsible for achieving the business plan and from their point-of-view, any process that they must use, and which is not effective, is an obstacle. These managers see centralized product change as an encumbrance, not an asset. As a result, work around systems are used in place of the central system to meet the requirements of the business plan. This inevitably leads to different systems at each plant and effectively to decentralized product change control.

This decentralized product change system leads to two problems. First, it is much more costly to do process improvement on multiple systems than it is on a single centralized system. Second, in a global manufacturing environment this inevitably leads to a mismatch between plants and central product definition. This mismatch is manifested in several ways including: difference in approved configurations, increased error rate in routine change, increased error rate in orders received, and increased use of work around systems to get product "out the door".

• Suggestion - Combine ownership of product configuration databases. There are often as many as three product configuration databases. Central change control manages the central database, individual plants manage their own plant databases, and the order entry organization manages a customer order database. Although these databases are connected to various degrees the fact that the different managers have different incentives and therefore different agendas can lead to significant differences between databases. Since these databases are the key to accurately transferring customer requirements from the customer to the assembly line any differences between them can lead to problems building the right product. Additionally, known problems in these systems often lead to whole groups of people dedicated to correcting finding and correcting errors. Combined ownership of all three databases would help bring the incentive systems into synch and in doing so promote behavior which facilitates proper coordination of the three databases.

Principle #3 – Speed-Up the Engineering Change Order Process

It can be shown using queuing theory that a reduction in the throughput time to process an engineering change has a disproportionately large effect on backlog; and therefore total turn around time. Additionally, this reduction in turn around time significantly reduces the need for "work around solutions.

• Suggestion #1 – Reduce time required to transfer change requests to central change control by using electronics data transfer. The same is true of standards and drawings that must be transferred back to the originator after approval. This time can be virtually eliminated through the use of electronic data transfer.

• Suggestion #2 – Move error checking upstream to the originator of the change request. Checking and correcting errors in engineering change requests can take several days at central change control. Providing the necessary information to error check at the plants saves time in two ways. First, it removes several days from the central change control process. Second, it makes the originator more efficient by making it easier to get the information necessary to write an accurate change request.

• Suggestion #3 – Make change visible to other plants as soon as the change is initiated. This serves two purposes. First, it allows all activities making change on the same product to see other change already in the system. This prevents duplicative changes and changes which are mutually exclusive. Second, it helps move the agenda process, which involves getting approval from all parties concerned with change on that particular product, forward. Moving the agenda process forward speeds up the central change process.

Principle #4 - Reduce Impact of Variety

The final principle takes the occurrence of engineering change as given, and focuses on minimizing the impact. Product-product couplings, which exist between two interacting components that are part of the same system, are the source of much of the difficulty with product change. These problems are best addressed by product architecture. In particular, systems that are more modular and make use of standardized parts will experience a reduced impact from change since parts are more readily accessible, substitute easier, and reduce the total number of parts that must be managed.

• Suggestion #1 – Pursue a Modular Product Development Strategy. To efficiently customize products for individual customers requires a modular product architecture that determines what types of components will be used and what linkage system will connect them to make specific products for individual customers. Modular product architecture not only reduces the effects of product-product couplings, it also serves to create product lines that can be easily, quickly, and most important cost effectively customized. In other words, it simplifies the problem of supporting a customer led strategy. This Suggestion requires significant commitment and dedication of resources, which are beyond the scope of this project, however, this investigation supports other existing projects which will continue to pursue this issue.

• Suggestion #2 – Standardize parts used across the product lines. One of the keys to minimizing the impact of product change is to reduce the internal variety to the point where products can be built flexibly without the cost and time delays of setup changes. This can be accomplished through the use of standardized parts, features, materials, and processes in the design phase. This is generally an easy sell for smaller inexpensive parts such as fasteners, however it also holds true for more expensive components.

• Suggestion #3 – Develop and use a product configurator. Configuration software, known as "configurators" have been developed to keep track of all the options and features and all the rules that apply to their use. These configurators are capable of managing the relationships between options at a very detailed level and can be extended upstream towards the customer to provide an interface which "knows" all the features, options, and prices as well as all the rules that govern dependencies, conflicts, and constraints. The configuration "engine" can do the necessary calculations to resolve complex relationships quickly to provide the best solution to meet customer needs based on the available options.

Product Change control has received little attention in the context of benchmarking or lean manufacturing. This is in part because each industry has different constraints with regard to product change. These principles will need to be tailored to fit the exact situation; however, if used as a guideline they should speed the change process and simplify the change problem regardless of the industry.

REFERENCES: None

ACKNOWLEDGEMENT: This is a March 29, 1999 revision by Gene Goodson of an assignment for OM742 contributed by John E. Braun.