A Virtual World of Live Pictures.

Write your own ERP? Are you crazy!

I’ve been in the ERP space for many years, and more than a few clients have told me that they had written or wanted to write their own ERP.

I sell Microsoft Dynamics, so you can tell I have a great interest in discouraging this. It’s bad for business for customers to write theirs! Well that’s true in a way. It sure is bad for the client’s business.

There are more than enough customers who need ERP systems (especially cloud ERP like the one we sell) that one more ERP sale would make a big difference for my business.

I wrote about this years ago with my article (here on Ezines) on ERP vs Microsoft Access. This is an updated version.

The 2 reasons why people try to write an ERP

One: They had a bad experience before and feel like they need to control their ERP. The idea of ​​creating your own seems less risky than choosing another bad ERP.

Two: they think ERP is too expensive and that they can write their own more cheaply.

Let’s deal with reason 2 first.

Writing your own ERP is not cheap!

ERP systems are built from thousands upon thousands of hours of programming. I don’t think most small businesses really appreciate this. It takes many hours of programming effort to build a system.

Even really basic MRP systems would require 2-3 “man years” of effort to build and be usable.

An average ERP implementation in a small or medium business takes between 800 and 1000 hours. That’s the time of your staff (about half that of consultants).

To write yours well ERP, you need a program.

Let’s use $ 80,000 a year as salary. That’s a VERY modest salary plus benefits for a programmer. Either you’re not getting a great developer (if it was great, I’d be working at Google) or someone has no idea what they’re worth.

To be realistic, it will take 3 men. years effort to build the ERP.

That is $ 240,000. You can get a really good ERP delivered and installed for $ 240,000.

Isn’t it cheaper than a regular long-term ERP implementation?

Let’s take Dynamics Business Central as an example, as I know this very well.

No, it’s not.

I will post a link to a Dynamics 365 ERP pricing guide at the end of this post. Consider a more or less “average” small or medium-sized manufacturing company.

The implementation of something like Business Central will be in:

  • $ 2000- $ 3000 a month for the software

  • Maybe $ 100,000 for implementation.

  • It will take 6 to 8 months to do it.

Your home ERP will not be usable for at least one year. Maybe two. You may have some incremental capabilities, but 80% or more of your team will continue to use manual systems for a minimum of 12 months.

The reason you need ERP is to get away from the hell of Excel sheets and manual processes.

There are even less expensive ERP systems like Oodo, but whether you choose Dynamics Business Central (which is cloud-based and starts at $ 70 a month per user) or Oodo, which has a strange pricing model that I haven’t really understood yet , you need a lot of users to cover the expenses of the $ 240,000.

Your ERP never stops costing you money

The problem is you own your ERP system. You break it, you fix it. You can Never fire your $ 80,000-a-year programmer. You must have them because they are the only source of technical support you will have.

And there will be an endless list of requests. They exist because you are writing your own ERP. The vast majority of employee wish lists will exist in whatever out-of-the-box system you need to get. Your DIY ERP system won’t have any of those features to start with. So you are paying your staff member $ 80,000 a year to write them one by one.

Flexibility and customization

The second reason people want to write their own ERP is because they have a bad experience the first time. This leads them to distrust the ERP process and feel that it is better for them to write their own.

This is what I wrote in the original article on creating a DIY ERP system in Microsoft Access.

Soon after your database is created and your purchase orders are shipped to vendors, you realize that you need to receive things. Suppliers are annoying, sometimes they ship exactly what you want, exactly in the quantity and price of the purchase order, but often they don’t. So as time passes, the simple access database begins an insidious march towards something deadly: COMPLEXITY!

As time goes by, it gets more and more complicated.

Find an ERP that you can customize yourself

So what to do with this? You really don’t want to be cornered into a corner where you have no options.

Get an open source ERP, of course.

Open source means that you can modify and customize the ERP yourself. The ERP system source code is available for a programmer to make changes. There are two open source models. Free open source (nothing is really free) and commercial open source.

Microsoft Dynamics Business Central – Business Open Source

Microsoft Dynamics Business Central is actually more of an ERP programming language than an ERP. It is written in a recently modernized language called AL, which is constantly being improved. This is derived from the old Microsoft Dynamics NAV C / AL language.

Some clients learned the AL language. They have done it almost entirely on their own. Within a few weeks, they were writing code on it.

It is not difficult to learn or code. It would be MUCH less expensive to start with a finished ERP and improve it. Your alternative is to start with a blank page and spend more than 6,000 hours programming. Then you could have something super cool and totally unique and very, very expensive!


Get a real ERP system like Microsoft Dynamics Business Central. The effort it takes to create your own full-featured ERP will be impressive. Get a “seed” ERP system that you can modify.

You will never save money by writing your own system.

Either you will provide a job for life to a programmer or you will end up like many clients. With a barely working mess that you replace anyway.

Leave a Reply

Your email address will not be published. Required fields are marked *