Skip to main content

Lessons in Lean (1)

When I wrote the Fingerspeller Flashcards, I thought I should pre-load the graphics (and the dictionaries) so that when a character is displayed, it is available instantly.

This had a small problem with it: Each alphabet, say ASL, has 26 to 30 images (actually more, since each letter needs at least 2 images) and each image is 30KB. So I had 1 MB of images plus the program (another 200KB), so all in all some 1.2 MB of data had to be downloaded before the program was ready to go.

This has a major disadvange: With a 128Mbit/s ISDN internet connection (very fast dialup, equal to 16 KByte/s), it took at least 75 seconds to get the application ready to go. Even my 3.5 Mbit/s Cable connection needed almost 4 seconds (although 4 seconds is fast enough that I didn't think about it much). But the long delays made the program unusable for most of my users.

The program only displays one letter at time. But it was downloading all the images in advance, just in case one was needed, and this meant none were available for a minute and half (and even a basic DSL line needed 40 seconds), longer than most users are willing to wait. If it would load just what it needed, it could be ready much sooner.

This is like writing detailed specifications before you start implementing. You have so much specification, just figuring out where to start take a significant amount of time. You can't see the forest for the trees. And because everything is "Must have", the whole project must be finished any value can be obtained from the project.

This is the biggest drawback of the procurement process as practiced by the Swiss government and other big institutions. Massive, very detailed specifications produce huge projects which must be implemented in their entirety before they can be used at all. A product that can't be used has no return on investment.

Time to ROI is probably the most under-appreciated cost factor in software projects.

How did I solve my problem? Easy: load the images on demand. There is a delay of 1.5 seconds between the point when I know I need the image and when I actually have to display it, which at 128Kbit is enough to download 24KBytes. This is "Just in Time" Delivery.

So I changed to code load images only on demand, and did some other compression on the HTML and javascript. In the second iteration, I reduced the image size from 30K to 15K. Result: The start page now needs about 2.7 seconds to load on a 128K line.

I need to find a way to get the images down to 8K (suggestions on how to do so would be most welcome!) to make the process really robust, but the improvement was immediately visible in my Google Analytics stats.

This is Lean Thinking. Eliminate waste, focus on delivering value, and improve continuously. This is also Scrum, with its plan - do - evaluate - improve loop, which focuses on implementing the most important functionality this month, getting it done, and then repeating process next month.

Comments

Popular posts from this blog

Scaling Scrum: SAFe, DAD, or LeSS?

Participants in last week's Scrum MasterClass wanted to evaluate approaches to scaling Scrum and Agile for their large enterprise. So I set out to review the available frameworks. Which one is best for your situation?

Recently a number of approaches have started gaining attention, including the Scaled Agile Framework ("SAFe") by Dean Leffingwell, Disciplined Agile Development (DAD), by Scott Ambler, and Large Scale Scrum (LeSS), by Craig Larman and Bas Vodde. (Follow the links for white papers or overviews of each approach).

How to compare these approaches? My starting point is Scrum in the team. Scrum has proven very effective at helping teams perform, even though it does not directly address the issues surrounding larger organizations and teams. An approach to scaling Scrum should not be inconsistent with Scrum itself.

Scrum implements a small number of principles and constraints: Inspect and Adapt. An interdisciplinary Team solves the problem. Deliver something of va…

Sample Definition of Done

Why does Scrum have a Definition of Done? Simple, everyone involved in the project needs to know and understand what Done means. Furthermore, Done should be really done, as in, 'there is nothing stopping us from earning value with this function, except maybe the go-ahead from the Product Owner. Consider the alternative:
Project Manager: Is this function done?
Developer: Yes
Project Manager: So we can ship it?
Developer: Well, No. It needs to be tested, and I need to write some documentation, but the code works, really. I tested it... (pause) ...on my machine. What's wrong with this exchange? To the developer and to the project manager, "done" means something rather different. To the developer in this case, done means: "I don't have to work on this piece of code any more (unless the tester tells me something is wrong)." The project leader is looking for a statement that the code is ready to ship.

At its most basic level, a definition of Done creates a sh…

Five Simple Questions To Determine If You Have the Agile Mindset

My company has started a top-down transition to Scrum and Kanban. Will that make us an Agile company? About 2 years ago, I attended a conference hosted by the Swiss Association for Quality on the topic of Agility. As a warm-up exercise, the participants were given the 4 values of the Agile Manifesto, then asked to arrange themselves in space. How Agile is your company? How Agile do you think it should be? Very Agile on left, very traditional on the right. There was a cluster of people standing well to the right of center. “Why are you standing on the right?” It turns out that they were all from the railway. “Our job is to run the trains on time.” They were uncertain whether this agility thing was really aligned with their purpose.
Is Agility limited to software? Steve Denning has collected the evidence and laid out the case that Agile is not limited to software, nor is it merely a process, nor is it something you can do with part of your time, nor is it something you can have your …