Critical path: What is it? And why do you need one?

Does the phrase critical path feel you with dread? Or make you jump for joy? When it comes to manufacturing a product a critical path is…critical!

In this article I cover exactly what a critical path is, and when and why you need one. You’ll also find out how to create one, and most importantly, keep it updated.


A critical path is:

Lots of people are scared off by the term ‘critical path’, but it is simply a project management document for each product that you make showing key dates.

Creating a product has lots of moving parts, many of which are dependent on each other. So that one can’t happen before the next.

For instance, if you are creating a leather bag you can’t make the bag until the leather arrives. Knowing when the leather is going to arrive is critical to getting your bag made.


Why you need one:

Having a critical path ensures that you hit your deadlines, especially if your product is seasonal.

An example:

  • You want to have swimwear on your online store in time for the summer. You probably want it no later than the beginning of May.
  • Your manufacturer has a lead-time of four weeks for production, from the date they receive your fabric, you will need to get the fabric to them at the very beginning of April, if not sooner.
  • The fabric takes six weeks from the date you place your order to the date that it arrives in the factory, you are going to need to order your fabric mid-February.
  • You want the fabric dyed to your specification and it takes 4 weeks to receive labdips for the colours, you are going to have to order the labdips in the middle of January.

A critical path is a great aide memoir because you map out how long every single process in your supply chain is going to take. It also gives you a reality check as to whether it is actually possible to make what you want to make in the timeframe that you have.

You can share your critical path with the factory so that they know when your materials are coming. Remember that the factory won’t start work until they have received everything. (It also makes you look super organised!)

One of the key things that I see going wrong with manufacturing is when a factory and brand agree on a production start date but then the materials or trims don’t arrive on time. Yet the brand then expects the factory to still finish the production on the same date.

A critical path means that you take ownership of your own production. Or you could pay a production manager to do it, but it’s really very simple.

How to create one:

You can get fancy software that will help you manage your product critical path which is called a PLM (Project Lifecycle Management).

But, it is just as easy to either create your own spreadsheet. You can even put the dates on a google calendar or in a paper diary. These methods will do the same job as a PLM, especially with smaller factories.

The key thing is for you to be able to note down and see which dates are dependant on other dates in order for production to happen.

1. Make a list of all of your components

Include every single component that goes into a product:

  • raw materials
  • include printing, embroidery, embossing, etc.
  • trims (buttons, zips, additional components)
  • labels (inside and out)
  • packaging
  • you may also include embroidery or other processes that might take place elsewhere

2. Find out the lead-time from placement of your order for each component

Don’t forget to add in time for anything that needs approval. For instance, if it is a fabric you are doing in a particular colour how long will the labdips take?

3. Make a list of all of your production stages

For example:

  • Prototype sample – this is often made in sample materials with no trims. It’s used for fit and design approval.
  • Pre-production sample – this is your contract with the manufacturer. Every detail on this sample must be correct. If the sample is not correct then comments need to be made on the contract

4. Start plotting everything on your critical path

When plotting your information, bear in mind what is dependent on what. Start from the date you want everything and work back.

For instance, the manufacturer will not start making your product until all of the raw materials and components have been received.

Check – is it going to work in the timeframe that you have? Are you being realistic?

Top tips for creating your critical path:

Don’t forget that manufacturer lead-times can change throughout the year, particularly with seasonal products. If they’re a knitwear manufacturer everyone is going to want their knitwear delivered before winter starts. Meaning lead-times will be longer.

It’s always best to ask a manufacturer “What will your lead-time be if I place my order on this date?” They will generally have an idea based on what they were working on in previous years.

It’s always better to allow some leeway for unforeseen circumstances. The factory may experience something which causes it to close or work at reduced capacity –  such as a pandemic! 

In order to get to the dates you want, YOU need to make sure that you approve things as soon as you can. One of the main reasons that manufacturing times go out is because a sample was not approved on a set date. This can impact all of the future dates.

Stick to the dates on your critical path. Advise your manufacturer as soon as possible if you are going to miss them. This means that they know they are going to have a gap they need to fill in their production. Don’t be surprised if you miss a date by a week and it adds considerably more than a week to your manufacturing lead time. The manufacturer will then have to fit you in when they can.

Do you need one if you are making your own products?

Even if you don’t feel you need a critical path right now it is worth getting into the habit of creating them. Even if you only have one product.

If you are producing your own product, chances are you have raw materials that go into making it. And if you have a certain product you want to go on sale by a particular date, e.g. Christmas, you need to work backwards based on how long you and your team will take to make it.

A critical path is the best way to track your production process and make sure you hit each deadline.

Want to listen to a podcast on this topic? Check out episode 158 of the Make it British Podcast ‘What is a critical path and why do you need one?’