PCB Librarians and SMART PCB Component Management
In the 1972 classic movie “The Candidate”, Bill Mckay, played by Robert Redford, ran for the
State Senate. Although he was a long shot and an underdog, McKay ends up surprising everyone with an incredibly close win. After the concession speech of his opponent, a vast mob surrounds McKay. He fights through the crowd, trying to reach his campaign Manager Marvin (played by Peter Boyles). Finally reaching him, he pulls him aside into a hotel room, and Robert Redford sits on the bed and after several seconds of silence finally asks a very pointed question “So, what do we do now? ” The campaign manager has only a bewildered look. Bill McKay asks the question again…. “What do we do now?” By that time the horde had found them, and they are quickly pulled back into the hallway.
What do we do now?
Sometimes, the radical steps we take in the first Pillar of Singularity have us asking the same question——“What do we do now? ” Having only a single library is only the first major battle in this war. It might be a novice ideal, but just because you have a single library does not mean that it is actually “Managed” or controlled. All you may have is a single pile of trash.
The task of erecting the second pillar is before us. The library must be “Managed.”
What is meant by “Managed”?
The “official” definition of managed is “to be responsible for controlling or organizing someone or something.” I am not sure which is worse, to have multiple libraries or a single library which is unmanaged. They have the same result of producing a bad PCB Design. So what is the management plan anyway?
The management plan for our Library has four categories: revision, lifecycle, roles, and permissions.
Revisioning is the process of managing different drafts and versions of documents or items. As items change in the library, we create various versions to document the history, which we can easily refer to later if needed.
Revision Control Systems
Revision control systems are like noses. Every company has one, and they all seem to be different. Whatever revision system your company uses, the bottom line is that your PCB library follows the revisioning scheme as closely as possible.
But not everything in your PCB library has the same versioning scheme. For example, some components have a simple singular numeric numbering system where the first version is -01, the next a -02 and so on. Other things, such as the entire PCB Design package, must have a more flexible versioning scheme.
With a simplified Numeric Alpha system such as 1.A, you need a thorough procedure in place. A common system uses the numeric to signify changes in the design. A significant change is anything that requires the creation of New Gerbers. With that, the numeric would be bumped up, all other changes (Minor) would only impact the Alpha designator. In doing so, this allows for much better control of changes in much more detail, as needed.
Let’s walk through this. We start a design and the revision level is 1.A. We find though, that further changes are needed; these changes do not require new Gerbers. A good example would be a correction on a Fabrication or Assembly drawing. The changes are done and the design package is bumped to 1.B. The next change requiring new Gerbers results in the Numeric being bumped up to 2.A.
Most likely, revisioning is something out of most PCB Designer’s control. However, most important is to determine that Revision scheme beforehand. Making changes mid-stream causes problems and confusion.
Very closely related to the Revisioning scheme of the PCB Design is lifecycle stage. It is used to describe and define the maturity of a specific item. Although every company will be different, there are usually six current product lifecycle stages: introduction, growth, maturity, decline, phase‐out, and obsolescence.
The individual names for each stage may vary in your situation. The best-managed systems are those that change the lifecycle stage automatically. Secondly, whenever changes occur, the lifecycle automatically returns to the introduction state. In this way, all changes will be understood and can be reviewed. As we will see shortly, these changes must go through an audit process. Those automatic lifecycle changes are useful markers of the items up for review.
Also, essential to keep in mind, the lifecycle does not just apply to components. Anything in the database can have a lifecycle. However, there are items that do not deprecate as a component would. For example, an SOP or reference document will have revision levels but not deprecation.
I must clarify something further. The component lifecycles are different based on the scope of the lifecycle. To adequately describe every possible state of a component; which vary widely depending on the specific needs of a company, it should at least have the following rules of; New, Approved, Deprecating and Obsolete.
Being the first condition of a component, New allows components to be created in the library but placed in a sort of isolation. This initial state identifier indicates that it still needs to be checked. We will look at this in more detail later.
Once the component has been reviewed and checked, the component state changes to Approved. Before any design moves to Fabrication, all components should be in an Approved state. Setting a procedure that does not allow a PCB to move forward until each of the individual components used is verified will protect the design from any unforeseen problems.
As the lifecycle of the component progresses, it will begin to enter the End-of-life stage. The common reasons for component deprecating are, either the component manufacturer has determined that it is no longer financially viable to continue the product because of a drop in sales, or because of material shortages.
The final stage is the obsoleting of the component, when it falls off the market entirely.
One-Way Street for Component Depreciation
I recently took a trip up to the Los Angeles area. I felt rather brave that day and decided to drive. What a crazy time that was. It was challenging to maneuver the freeways. A massive concrete web of roads was going every which way. It resulted in me missing my turn off… a couple of times. A perfect trick to get where I needed to go was to watch the signs and be quick to act consistently.
The same is true regarding the components in our library. Once a part begins to deprecate, it rarely recovers from that condition. That is a one-way street and we must be very careful always to be very quick to respond to it.
Lifecycle Component Assessment
Since every component ultimately is obsoleted sooner or later, we have to determine if it is possible to design them into a new product. Usually, this is not a problem if the product is intended to have a short lifecycle. However, if the product is expected to be in the market for an extended period, it is advised to conduct a Lifecycle Component Assessment (LCA).
Our present crisis has made it difficult to complete a good LCA. What I am speaking of is the worldwide component shortages that play havoc on our entire industry. With lead times for a variety of product lines increasing to as far out as 52 - 80 weeks, it is vital to be proactive, watch those signposts and take the steps as early in the process as possible.
Various individuals are involved in the design process before it is all finished. We must clarify the roles and responsibilities of each. With slight variations, some of the functions involved include; Project Managers, Electronic Engineers, Mechanical Engineers, PCB Layout, PCB Librarian, QA/QC Assurance. Instead of going into detail on each of the roles, I’d like to concentrate on one of them: PCB librarian.
Just as crucial to the data itself, the PCB Librarian is who can make any changes on that data. This is actually controlled by limiting these individuals. The librarian’s first responsibility is to create all components making sure that they are following the IPC standard, besides making sure that the components are in the correct place in the library, (which we are looking at in more detail in the upcoming chapter) where they can be found and used quickly. So, the librarian should be an individual with a good understanding of components, the standards to design them and a knowledge of the structure of the library itself.
When I continued my investigation of the company mentioned in the previous chapter, I found that any person who could get into the system could ALSO make ANY changes in the library. It was a recipe for disaster. But this does not mean that the librarian role should be taken on by someone who does just component design. Most likely, the librarian role will be taken by someone who has multiple positions. That is much more realistic.
Permission levels are closely associated with roles. If Roles defines who can have access, then permissions answer the question, what can they do?
Some individuals may only need to view certain information. Others might need to use that information in some way, and still, others might be required to modify the data of these roles/permission levels. Permissions keep things managed and in control of who and what.
Altium Tools and the Second Pillar
Whatever software you use to control your Library, it must have the ability to set up the Roles, Permissions, Revisions, and Lifecycle.
ACTIVEBOM® for Lifecycle Component Assessment
When you look at all the available ECAD Software packages, their use accomplishes pretty much the same basic things. Every now and then a product comes along that changes the entire paradigm of not what you do but rather how you do it. Altium is one of those companies and, with the release of version 18, has transformed the ECAD industry, especially with the release of the brand-new feature, ACTIVEBOM.
Before you conduct a Lifecycle Component Assessment, you must pass the BOM over to the procurement group, who check availability. Then, the procurement group reports back on any problem components for the design. If knowledge is power, then the lack of knowledge is feebleness. Knowing when a part was starting to deprecate was not only difficult but out of the scope of a PCB designers’ role.
Now the design is merely put through ACTIVEBOM, and within moments you have all the needed information. The ACTIVEBOM is a BOM tool on Steroids. It gives the availability of components, and if it is, should be used. Since this is a very dynamic area; it is something we run every chance we can get to see if anything has changed.
- Determine the specific items to store in the library.
- Determine what management systems you intend to use for each one of those items.
- Take designs through the ActiveBOM and determine if any hidden problems exist.
With ACTIVEBOM, we can be proactive to conditions of the industry and have that information as quickly as possible, up front. Remembering that the depreciation process for a component is a one-way street - this situation will not get better - most likely it will be worse over time.