Recently I've read several posts about PLM vs ERP. First, one from Oleg Shilovitsky about the differences, and one from Arena Solutions about how they might work together. We often hear this as a big challenge in our PLM certificate classes from many students. This is an important topic, and one that can cause a lot of contention in any business. I want to address some basic issues and see what you think.
PLM - ERP - What's the difference?
The most basic way that I can think to categorize the difference between PLM and ERP is this: PLM manages the virtual product and ERP manages the physical product. The virtual product must ALWAYS match the physical product, and thus the two must be seamlessly connected. This requires integrated systems that include sophisticated configuration management tools to accommodate changes and updates.
Choosing the right tools
Given the complex nature of keeping PLM and ERP synchronized at all times, we must decide which tools are best suited to do this. ERP tools tend to be very transaction oriented. Their goal is to move a product from one step to another until it is complete. ERP systems must keep track of parts inventories, resources needed to manufacture the product, available tools and processes, along with costs and scheduling of all activities. ERP tools are great at making sure all the steps for manufacturing happen on time and under budget.
PLM on the other hand is usually tied to 3D CAD models and accommodates changes, options, modifications, and frequent updates to models parts and products. PLM is also a very visual environment, with many people looking at models, exchanging ideas, and viewing the product as it is designed. PLM is also very collaborative: a group of people must often review any updates or changes as they happen. Engineering review often happens across the globe and around the clock as many engineers and designers are involved. Understanding changes requires sophisticated visualization tools that allow models, parts, documents, and other information to be shared in real time.
PLM must also manage changes and links to CAD files, assemblies, docs, test data, software, EDA files, and more. PLM must always provide an updated view of the As-Planned, As-Designed, As-Manufactured, As-Maintained, and other views of the product information. Product information must also be connected to the product requirements documents so there is always a link to the original specifications.
When we look at the tools needed to manage all the permutations of products throughout the product lifecycle, it is clear that PLM is much more suited to this task. PLM can always track the changes to the products out in the field, and then easily use that information to start creating the next version of the product; ERP has no such tools.
Who owns the data?
There is always a big argument about where the data should be mastered, and who should own it. The truth is, ultimately, the company owns the data; ownership changes as the product moves from one state to the next. While the product is in Design, the data is owned by the PLM system; while the data is being manufactured, the data is owned by ERP. Once the product is out the door and in the field, it is owned by the Service group, or Warranty, or whatever you want to call it. It does not really matter who owns the data as long as the most up to date version is always tracked very carefully, in PLM.
Start at the beginning
To me, it makes sense for most businesses to carefully master their data in PLM at the beginning of the product lifecycle. PLM is where the product starts, and any mistakes made here will eventually find their way into ERP. Over the years many companies have gotten use to fixing problems with unclear, incomplete, or incorrect information coming from ineffective PLM systems during the manufacturing process. Companies have also invested almost nothing in PLM when compared with the millions upon millions of dollars invested in ERP. Is it any wonder that most PLM implementations leave a lot to be desired?
PLM supports product innovation
ERP does not readily support product innovation. ERP supports innovation in manufacturing processes and technologies, but not product innovation. Innovative products are imagined and created during the PLM design activities, and not in ERP. By the time you get to ERP it is too late to add much product innovation. Commitments to product innovation are locked in during the PLM phases of product development. This supports the need to invest in more and better PLM technology to support the goal of creating more innovative products.
There are certainly exceptions to what I have said here. Many process industries, like CPG, food and beverage, chemicals, and others will be much more ERP-centric. Also, those companies without the goal of creating new and creative products, but only cheaper "knock-offs" will want to invest more in ERP. Products without much 3D CAD and those that have little engineering IP may not need a ton of PLM.
In my experience, most companies have under-invested in PLM. With PLM you can create innovative, higher quality products that get to market faster. If you are a manufacturing company that wants to create innovative products that delight your customers, and if your products require strong engineering design with 3D CAD models, you will want to invest more in PLM than you do in ERP.
What do you think? Have you invested enough in PLM?