Making Kitchen Knives – Part 8 – First Evaluation

First thing first – today I tested the very nearly finished knife when I was cooking shrimp for lunch.

©Charly, all rights reserved. Click for full size.

It handles well and cuts OK, but I really suspect it won’t hold an edge as well as it should. But the cheapo wood looks way more posh than I expected it, ammonia fuming really, really improved its looks.

And now to the boring stuff.

What I am doing here is actually a small-sized DMAIC project – an abbreviation for Define-Measure-Analyze-Improve-Control. It is a process used in industry to bring some logic and use of scientific method into improving manufacturing processes. Although as everything in today’s corporate culture it is used wrongly and heavily abused and misunderstood all over the place, because american-trained managers …. wheef, do not get me started on american-trained managers.

Aaaaanyway, in the first phase, Define, you should either define your problem or your goal or both. In my case, I have a specific goal – to get my manufacturing time of this type of knife under five hours of manual labor.

In the second phase you should acquire all measurements that you need in order to do something about it – in my case I have measured the manufacturing time of each distinct step in the process.

And now, in this post, I am performing the Analysis of said data. Total manufacturing time: 10:46, or 646 minutes.

A picture is worth a thousand words, so here is a picture.

©Charly, all rights reserved. Click for full size.

There are of course multiple approaches one might use, but in this specific case I think that this suffices ample enough – it is so-called Pareto Graph. The balks are actual times in minutes for each step, ordered from the highest to the lowest. The black line is a sum of the relative proportions of these times to the total as one progresses from left to right. As you can see, I have ten distinct manufacturing steps and from those five steps constitute 90% of manufacturing time. These are the steps where I have to concentrate on actually reducing said time, because here my efforts have the biggest payoff. That does not mean that improvements in the other five steps are not worthy pursuing at all, but they are not worth pursuing at this time.

I have done one thing that is not normally done, that is I sorted from get-go the steps into two categories – low hanging fruit, where I think I can do improvements without too much hassle and without obtaining expensive or complicated equipment, and high-hanging fruit, where I can save time only through acquiring new skill or new equipment or where I think saving time is not actually possible in a meaningful way.

Now comes the next phase, which is  to improve the process. I will try to implement some of the ideas for that I have expressed and make a batch of multiple (~10) knives with improved process. We will see how it turns out.


  1. Ice Swimmer says

    The shape of the knife is to my eyes quite original and it looks more like a kitchen knife than many other kitchen knives. I like the curves and the rounded tip.

    So, about half of the time goes to the final finishing and polishing, the results of which are the things the customer will see and feel just about first.

  2. says

    You’re right, the wood does look posh, and like Ice swimmer, I like the rounded tip. It’s not like I need a pointy tip in a knife that size, I won’t be removing potato eyes with it, but I have clumsily dropped knives (no more ceramic knives for me) and not having them stick out of my foot seems like an improvement.

  3. rq says

    I like the rounded tip! It looks like you can get a nice rocking motion for slicing and dicing, I like that. And the handle looks great, too.
    Now, what were you making…?

  4. voyager says

    Fascinating. In nursing we use the cyclical process of assess/plan/implement/evaluate.
    I also like the curved knife tip for all the reasons that Giliell and rq do. It’s distinctive, beautiful and functional.

  5. jazzlet says

    I also like the rounded tip and the whole blade shape, as rq says good for slicing and dicing, also good for chopping herbs. The handle shape looks comfortable for extended use and the wood has come up beautiful.

    I’ll be watching your progress with interest, good luck!

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