What is the goal of part numbering system?
The goal of any
part numbering system is to uniquely identify the component approved for a
specific application. Accurate, consistent, unambiguous part identification is
essential for correct product assembly, testing and maintenance.
Part numbering schemes
Intelligent – Traditional
part numbering systems and document identification schemes originated over 50
years ago. At the time, a basic consideration was that unstructured information
was very difficult to find, and it was therefore necessary to overload document
identifiers and part numbers with search-related "helper" data.
In other words by looking at the P/N
one should be able to have an idea of what the item is. In this case the P/N
really becomes the description of the particular part (or assembly) and usually
each digit in the Part Number has a particular meaning.
With this type of scheme, a part
number generated for a capacitor might be for example CS-100-03, where “CS” stands for capacitor,
“100” is the capacitance in ohm and “003” is the serialized suffix.
There's an almost interesting fascination,
with designing the perfect part numbering system. Everyone starts by
envisioning how convenient it would be to tell, at a glance, the important
characteristics of a part, or the document number that describes the part.
Advantages of intelligent part numbering
Significant part numbers offer time savings downstream, and they can help
prevent data entry mistakes and improve manufacturing efficiency. Here’s how:
·
Searching efficiency: With Intelligent
part number you can search for and find particular types of parts from just the
part number. Searching for *CS* might show you all the capacitors that a company has
assigned part numbers to for example. This is really handy if you are designing
something and need some particular capacitor in the design. You have to find
out if the capacitor you want to use already exists in the company or if you
need a new number. By searching on the part number(“CS”) with some wild card
characters it’s easy to see where all the capacitors and are they already released
·
Reduction in error: Descriptive
part numbers specify the group to which every part belongs, so you can
immediately see when a part is in the wrong group.
·
Process improvements: Because
parts with similar naming conventions are all handled the same way, you can
predefine the change routings, review processes and manufacturing steps for
each part number class or category.
Disadvantages of intelligent part numbering
·
Training
and knowledge required: Mistakes are often made in encoding the part
description into the number, some of which can be quite costly. The engineers
who "know the code" use the part number, everyone else reads the part
description. If a part's number says
"10 amp fuse" while the description is
"1.0 amp fuse", a lot of product can get shipped or serviced with the
wrong fuse.
·
Error Prone: You can
never simply ignore an incorrect part assignment. Otherwise, the category
number becomes an unreliable indicator of its content. An aluminum casting
that's accidentally assigned to the steel castings category requires an
engineering change and full dispositioning. And the error becomes more painful
if your number has been cast, engraved, etched or printed on the part. If there
are a series of items (O-rings, screw lengths, resistors) with a common base
number, one bad part assignment may block a future assignment, and therefore
require that the entire series be renumbered.
·
Inefficiencies: You may need a
specialist to handle most part numbering if you use a significant scheme. In
this case, a single person or group can become a bottleneck. And pulling a part
number may require time and discussion, which slows down the design process.
Non-intelligent – On the other side of the battle field is the army of people that say that a Part Number should just be a number, any number, that is just unique to an item and doesn't tell you anything about what the part is. Also referred to as “non-significant.” (not descriptive), all numeric and as short as possible .Non-significant part numbers are typically serial (pulled in numerical order), regardless of the type of part.
Everything has a name and a number associated with it within a company, even the employees. Have you ever cared what the employee number is of a co-worker? Probably not, you are more likely to care about their name. The same logic follows when talking about part numbers in an Insignificant Part Numbering System. The number a particular part has isn't important in an Non-significant Part numbering system, but the description (or name) is. Numbers are usually assigned in numerical order by a specialized computer program like a Product Life Cycle Management (PLM) system. That's the thinking with non-significant part numbers.
Using this part numbering system, a resistor could be assigned part number “P1000012” any unique identifier.
Advantages of non-intelligent part numbering
Using this type of scheme will save your organization time upfront. You can
ramp new employees quickly, avoid relying too heavily on any one person and
maintain the system without much overhead. Here’s how:
·
Faster to assign: It takes
little to no time to pull a sequential number for an item. Assigning a part
number can happen fast.
·
Little efforts needed: Easier
data migration efforts for legacy to new system. Easier Merger & Acquisition
efforts.If your organization hires new employees they will not need to learn
how to define a part number and can focus their attention on other tasks.
Assigning a new part number can happen with minimal training.
·
Simple maintenance: It is easy
to maintain this type of scheme, as it’s essentially a sequential list! You
will not have to decide where and how a new part fits into your scheme.
Disadvantages of non-intelligent part numbering
·
Requires a business
system to search parts: Because it doesn’t have meaning, a
non-significant part number does not provide any cues to help a user evaluate a
part. In order to navigate through spreadsheets with randomized part numbers,
you need a system that can search for parts based on description, name, size or
other relevant attribute .
·
Error prone : With
insignificant Part Numbers you have to search in the description field to find
all the wire that the company is using. This can be OK if the description
fields are all the same, like all wire used in the company has the word
"wire" in the description but that isn't always the case. Description
fields in most Part Number databases are limited to some small number of
characters like 40 for example so the tendency is to abbreviate.
"wire" "cable" "condt" "harnss" might
all be in the descriptions so if you are looking for wire it might not be that
easy to find with Insignificant Part Numbers. Only if strict discipline and
rules are established for how to name things can Insignificant Part Number
Systems be used successfully
Semi-Intelligent or Hybrid Systems - One way that I have seen this work well is using part category(eg Commodity Codes). Where the business rules are fundamentally coupled to the physical parts. For instance, in the vast majority of cases an "electronic component" number will be quite sufficient, and there's no need to create separate Resistor, Capacitor and Diode commodity code prefixes unless the physical parts are — and always will be — treated quite differently from one another. These parts types, even with separate and unique custom attributes, can all share the same part number format. Since these part categories represent clear and unchanging attributes, you'll want to keep the numbering groups very large.Another way of looking at semi intelligent part numbering system is using class codes to categorize the parts.
Of course, depending on how your company profile and product categories , part numbering system will defer Your business operations can also influence which part numbering system to use. An original equipment manufacturer (OEM) that creates its own part numbers has entirely different business needs than a company downstream in the supply chain.
Also consider your business tools. Will your current system support your part numbering needs? Can you maintain your part number system with your existing tool or will your part number system be more effective by bringing another system into the mix?
Here are some references from experts
Clement, et al.: Manufacturing Data Structures, page 20:
Another important point about item numbers is
that they should be as short as possible. Part numbers are keyed, copied and
used as verbal identifiers. The shorter the numbers, the more accurate people
can be. Obviously, the greater the number of digits in a part number, the
greater chance of error. We also recommend that only numeric digits be used.
Garwood: Bills
of Materials: Structured for Excellence, page 73 (author's emphasis):
The solution...is to use shorter non-significant part
numbers. We have found that part numbers of 5 or 6 digits are the most
effective.
Watts: Engineering
Documentation Control Handbook, page 49:
The most critical of these issues is that, over
time, the significant numbering systems tend to break down. ... As time passes,
variations arise which were not foreseen. One digit was set aside where two are
now needed. Significant numbers thus tend to lose their significance. They no
longer do the classification coding function intended by their inventors.
Though my first reflection on reading this article was to say, Intelligent Numbering system is the way to go.
ReplyDeleteBut your final conclusion that, Numbering systems depends upon on the Company profile and product categories is the key.
When I had a conversation with Design Engineer who had been in the Industry for couple of decades mentioned that, to get a change order approved, they would write it on piece of paper and the paper would go table by table for approval. Bill of Materials were maintained in Excel Sheets.
Imagining a situation like that without using Intelligent or Hybrid numbering system gives me a heart burn.
For High Profile companies which cater to different segments of market - Intelligent System is definitely a must-have. This time being the era of Internet of things, where the IT has developed drastically. Implementing a Intelligent numbering system would be advisable. There is always a lot of freedom to play with. There is overhead involved in Training. But its pays off in keeping the boundaries.
But, for a company which is dedicated on catering to certain segment, lets say, I'm gonna make only consumer goods, We can keep systems simple by implementing Hybrid.
Or Companies which doesn't manufacture, they just buy the off the shelf and assembles, and sell, definitely Hybrid.
Hi Ram,
ReplyDeleteThanks for your comments. Your points are very valid.
Also visit the PLM Group forum in Linkedin, i have posted this article in that group to ask broader group of people and see what they have to say.
I am sure you would be interested to see how traditional vs modern thoughts share their ideas.
Thanks,
Sumita
HI Sumita,
ReplyDeleteThat's a good article on part numbering - Intelligent Vs Non-Intelligent.
In my view , based on past experience, it is always a difficult situation and will continue to be, in choosing between the above 2 options. There is a lot of factor we have to consider here like the type of the industry, the current legacy situation (most of the customers having intelligent part numbers have only 60-70% accuracy and in some cases the intelligent part runs of out numbers for some group series) etc...
While there is a general tendency for most PLM consultants to favor non-intelligent numbering (as it is easier maintain) , the knack here is how efficient we are in facilitating the transition from Intelligent to Non-Intelligent numbering system without confronting the business stakeholders need.
Now, having the intelligence captured as an attribute to the part , only helps in "searching" the appropriate, while the business need here is more than that...easy identification using the intelligent part nomenclature at first sight and better navigability in a complex multilevel BOM without doing a deep dive into the part attributes. So how do we address the situation here...
Most of today's PLM systems have attained a level of maturity, where you can define alias (or pseudo part number) for a given item or part. While the primary objective here is to enforce Non-intelligent part numbering , the intelligent number codification can happen at the backend using the features like part classification.
Invariably it is the job of the PLM consultants to capitalize such features and enable a smooth transition to the Non-intelligent numbering system which is easier to maintain, causes lesser disruption and this requires a robust part number configuration logic.
Advantages here could be :
-Business stakeholders will be more than satisfied to see their intelligent part numbers in their Assembly by toggling the switch to Intelligent view
-Gives an opportunity for the business stakeholders to take delayed decisions on potential conflicts or wrong codifications minimizing the impact on the IT implementation schedule
-PLM system can continue to drive non-intelligent numbering as a primary authoring system and enable adoption by the end users in the long run..
Regards
Sriram
Sir Explain.
ReplyDeleteWhy did go for part number system ?????
what is use of part number system????
Regards
sathis