by Martin Eliasson
2007-02-24 08:04:22


Thinking Just In Time or sometimes Just-in-Time means Just-What-We-Need

The more inventory a company has,... the less likely they will have what they need.

--Taiichi Ohno

Example 1 - Jiingi web system

For the Swedish Jamboree Jiingijamborii a computer system [1] (warning!) has been developed for online registration of participants for all Swedens scout groups. On Monday the 26:th me and my friend who is camp responsible in our group tried to enter most of our participants into the system.

it took three our for two people to enter 16 participants!

Clearly a case of muda, but why does this waste exist?

A few observations (based on email conversation with the system administrators):
  • The system was overloaded and erroneous. We had for example to enter each participant three times due to crashing servers etc (so actually we entered 48 participants).
  • The system was overloaded because it had a bug which made it worse.
  • The system was overloaded because the 28:th was the last day for entering participants for the cheapest price, hence, there was a peak of load on the 26:th.
  • the system had been open for registration since the 10:th of December.
  • If a system is open for about two months, and then is overloaded the last three days, we have a case of uneven load balancing and should consider applying heijunka to the problem.
  • Probably, the reason nobody uses the system in December or January is because we cannot plan so far ahead. My scout group for example got a completely new leader team the 14:th of January as the new semester started. Many leaders have also a problem planning vacation so early. I would say we have an overproduction case here - someone built a system and deployed it at a time when it was not needed (and in a way could not be needed). And because the system was delivered way before it was really used, the bug that worsened the problem could exist in the system for more than two months without anybody noticing.

Screen shot of failing web app


Finally I've decided to talk to our main organizations people working with helping and supporting the different scout groups and explain Just-what-we-Need - we need systems that are easy to work with. We shouldn't say we lack leaders when the leaders spend time equal to a whole scout meeting just entering simple data to a web system, a task which can be speeded up to 45 minutes or so. For one leader.

Example 2 - the free Xerox machine

Our group, as many other Swedish group I guess, have over the years received old Xerox machines for free after a company has used them. Since Xerox machines cost money, getting one for free is good. Perhaps. It's like needing a fishing boat for sports fishing on weekends and getting a 50-foot 1960:s military boat for free.

  • The free machine is a big bulky thing taking up precious space.
  • Since the machine is big (much bigger than needed) putting it in the most effective place is often hard or impossible.
  • The machine needs service, sometimes it doesn't work when needed.


We buy the smallest cheapest solution that full fills what we really need and throw out the old Xerox machine(s). We actually did it and by throwing out even more stuff we really didn't need, used or could use we freed the space of a whole room which we eventually merged with the old kitchen.

Our new Xerox machine is a really small simple Samsung multifunction machine. It is also used as printer and scanner for our computer. It's really small which enable us to easily move it temporarily when we need it in different places (which we do about once a year). Looking at the copy counter we can see it's used a lot.

Maybe most importantly: before merging the kitchen with the room the Xerox machine occupied, the kitchen couldn't be used for scout activities or socializing. Today the new kitchen delivers value to both scouts and parents in our group by being usable for activities and by becoming the spontaneous meeting place we have missed for so long in our scout house.

Example 3 - cabinets

My leader team has recognized that a great deal of our leader time is spent moving around things in our scout house. The main cause is that the (too small) cabinet for our program material is located far away from the planning room. The obvious solution would be to create new cupboards in the planning room. We have also identified the space for the cupboards. In the planning room there was an old sofa nobody used. Ever. Removing the sofa will make plenty of room for the cupboards.

The cabinets is now built and we are very pleased. A key feature except for having all the things we use as close to the place where we plan, the cabinets are designed for storing boxes. This is a key feature because scouting is about action, we often go hiking and explore new places, so the things we use are better organized in boxes for quick relocation rather than openly in a cabinet or a cupboard like in a factory.


[1]The web registration system mentionend in article 1 is built using asp pages and SQL-server. It's my guess that any LAMP (Linux-Apache-MySQL-P*) solution would have handled the load without problem. Note that since at least 99.9% of all scouts will only participate as one scout and will only be entered once, all inserts/updates to the database is independent of another, so no database locking is required whatsoever. It's really a very very easy scenario from a computer science perspective.