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Yuval Yeret

Managing WIP isn't the same as Limiting WIP: Part 1 - 0 views

www.agilemanagement.net/...ManagingWIPisntthesameasL.html

kanban

shared by Yuval Yeret on 17 Jun 09 - Cached
  • To determine the truth of this we only need to look at the feature sets of the popular tools for managing eXtreme Programming and Scrum such as Rally, VersionOne, ScrumWorks, Mingle and very new tools like Borland Team Focus, to discover that not a single one of these tools allows you to set an explicit WIP limit. None of them provide a pull signal to start new work. Very few of them are even capable of reporting the quantity of work-in-progress.
  • s we learned more about the value of managing WIP, we introduced concepts to encourage and enable it, such as the use of Cumulative Flow Diagrams (a.k.a. Burn Up charts)
  • Agile teams encountering an impediment would generally mark a story as blocked and go on to another one
  • ...2 more annotations...
  • In a truly WIP limited process impediment removal is paramount.
  • So for those who would claim that Scrum and XP limit WIP and pull new work, such as Stephan Schmidt, I would point them to the feature sets of existing Agile tools. These tools do not impliment WIP limits, pull signalling nor are they particularly good at issue management and resolution. Recently, there are 4 new entrants to the Agile tools market. All of them producing WIP limiting Kanban tools including the same Mr. Schmidt. If earlier Agile methods had been truly WIP limited pull methods then tools from encumbent vendors would already reflect this. As a result there would be no market for new entrants such as CodeMonkeyism, AgileZen, LeanKit and RadTrack. More thoughts on managing WIP versus limiting WIP tomorrow... T
Yuval Yeret

Original Scrum-ban Article by Corey Ladas | Lean Software Engineering - 1 views

leansoftwareengineering.com/...scrum-ban

kanban SCrum agile ScrumBan

shared by Yuval Yeret on 19 May 09 - Cached
  • A problem with the basic index-card task board is that there is nothing to prevent you from accumulating a big pile of work in process. Time-boxing, by its nature, sets a bound on how much WIP that can be, but it can still allow much more than would be desirable.
  • then you need another mechanism to regulate the “money supply.” In our case, we simply write the quantity of kanban in circulation on the task board, and allocate new cards according to that limit.
  • You might have a simple principle like: prefer completing work to starting new work, or you might express that as a rule that says: try to work on only one item at a time, but if you are blocked, then you can work on a second item, but no more. In our example, that rule gives us an effective WIP limit of 6.
  • ...6 more annotations...
  • Just because anybody can have more than one item in process doesn’t mean that everybody should have more than one item in process. A problem with our multitasking rule is that it locally optimizes with no consideration of the whole. An implicit total WIP limit of 6 is still more WIP than we should probably tolerate for our three workers. A limit of 4 of 5 total items in process at one time still allows for some multitasking exceptions, but disallows the obviously dysfunctional behavior of everybody carrying two items
  • The ready queue contains items that are pending from the backlog, but have high priority
  • Here we’ve broken down in-process into two states: specify and execute. Specify is about defining whatever criteria are necessary to determine when the work item can be considered complete. Execute is about doing the work necessary to bring that work item into a state which satisfies those criteria. We have split our previous WIP limit of 5 across these two states. Specify is considered to take less time in this case, so it is given a limit of 2. Execute consumes the remaining limit of 3. We might change this ratio as time goes on and our performance changes.
  • Adding the specify-complete column communicates to the team that a work item which was previously in the specify state is now ready to be pulled by anyone who wants to move it to the execute state. Work that is still in the specify state is not eligible to be pulled yet. If the owner of a ticket in the specify state wants to hand it off, he can put it in the complete buffer. If he doesn’t want to hand it off, he can move it directly into the execute state as long as capacity is available.
  • e will also need some agreement about what results to expect at each handoff. We can do that by defining some simple work standards or standard procedures for each state. These do not have to be complicated or exhaustive. Here, they are simple bullets or checklists drawn directly on the task board.
  • The next event we might consider for scheduling planning activities is the concept of an order point. An order point is an inventory level that triggers a process to order new materials. As we pull items from the backlog into the process, the backlog will diminish until the number of items remaining drops below the order point. When this happens, a notice goes out to the responsible parties to organize the next planning meeting. If our current backlog is 10, our throughput is 1/day, and we set an order point at 5, then this planning will happen about once a week.
Yuval Yeret

InfoQ article: "Pulling Power: A New Software Lifespan" - 0 views

www.infoq.com/...pulling-power

BDD injection feature injection chrismatts product-ownership-101-list

shared by Yuval Yeret on 03 Jun 09 - Cached
  • how Kanban metaphor from Lean manufacturing and the Feature Injection template play into Behaviour Driven Development, working together to help us identify the most important software, reduce unnecessary artifacts at each stage of development, and produce the minimum necessary to achieve a vision
  • The artifacts signal each role to create further artifacts until the vision is implemented and the business value is earned
  • "Generating reports," he says, "is like lead. It's easy to work with, and it's cheap. It's also heavy, worthless, and drags you down. Developers sink a lot of time into writing report software. Why? Buy it, install it, hack it so it works. Use Excel. Don't spend money writing report software, unless you're the kind of company that sells them to other companies.
Yuval Yeret

Kanban development oversimplified: a simple explanation of how Kanban adds to the ever-... - 0 views

agileproductdesign.com/...kanban_over_simplified.html

lean kanban

shared by Yuval Yeret on 03 Jun 09 - Cached
  • It’s a lot easier to estimate a story that’s small — which can lead to more accurate estimates, and better predictability.
  • It’s easier to plan with smaller stories. With big stories — stories that might take weeks for a developer to implement — it becomes difficult to plan a development time-box — particularly when the iterations are only a couple of weeks. It seems that only a couple stories fit — and there’s often room for half a story — but how do you build half a story? Splitting them into smaller stories makes it easier to plan those time-boxes.
  • Shrinking stories forces earlier elaboration and decision-making. Where product owners could write their stories fairly generally and consider many of the details later, now breaking them down into smaller stories forces more thinking earlier in a planning lifecycle.
  • ...36 more annotations...
  • Managing little stories forces us to keep better track of how they fit together. Product owners are often asked to break down stories to a level where a single story becomes meaningless. To keep track of what’s meaningful to them and other stakeholders, they often need to keep track of bigger items such as the features of the product and how many stories contribute to building up that feature.
  • The result of these herniated time-box activities is a cycle that’s actually 3-4 times longer than our time-box. To get work done, we’ll use a time-box to elaborate stories, one to develop them, another to more thoroughly test them, and if there are bugs, possibly another to fix them.
  • During an ideal Agile time-box we’ll have frequent discussions between developers, testers, and those on a product owner team — like business analysts, user experience people, and business people. We’ll do this to understand what we need to build and describe what we’ll do to validate the story was really done. When time-boxes are short, there’s less time for this conversation. It’s common to move many of the conversations to detail the story and describe acceptance to the time-box before so we can be ready to really get moving with development when the time-box starts.
  • It’s difficult to fit thorough validation of the story into a short time-box as well. So, often testing slips into the time-box after. Which leaves the nasty problem of what to do with bugs� which often get piped into a subsequent time-box.
  • Anyone who’s attended an Agile planning meeting knows they can often last about an hour longer than you can stand it
  • As time-boxes shrink those on the product owner team and testers find themselves in a constant mode of getting ready for a next time-box and evaluating past time-boxes
  • work long hours, attend lots of meetings, and seem to have less time to be available to help developers with the current time-box. Since their focus is on a future or past time-box, questions about this time-box seem like interruptions. Collaboration decreases and tensions increase. Their work load is heavy, bumpy, not smooth or even.
  • Kanban cards are used to limit the amount of inventory the factory builds. It doesn’t do the Toyota factory any good to build doors faster then they can assemble cars. It just wastes money on excess doors, and parts of doors. Excess work in progress is considered to be waste in Lean manufacturing. (It’s probably waste in non-Lean manufacturing too.) In the above completely made up example, you’ll never have more than 15 finished doors hanging around. (Mudha is Japanese for waste. Learn it to impress your Lean friends.)
  • “Kan” means visual, and “ban” means card or board.
  • Kanban thinking in software development attempts to do a similar thing. We want to limit unnecessary work in progress to be no higher than it needs to be to match the throughput of the team.
  • In Kanban development: time-boxed development is out stories are larger and fewer estimation is optional or out completely velocity is replaced by cycle time
  • Exactly what’s left of Agile if we get rid of time-boxes, change the meaning of stories, and stop measuring velocity. And, exactly what do car doors and Kanban cards have to do with software development? Don’t get hung up on process. Remember, agile development isn’t a process.
  • You might have a column where business analysts spend time tracking down technical details that developers need to understand to write code.
  • These columns aren’t set. You should discuss with your team the phases that stories go through to be completed. Some organization may use columns for writing documentation, or preparing customer service people to support the feature in production.
  • The top is used for stories currently in progress in that phase. The bottom is the buffer. When work for that phase of the story is completed, it moves from “in progress” to the “buffer” where it’ll wait to be pulled into the next phase.
  • When we set limits for work in progress, we’ll set a total number for the process step that includes both “in process” and the “finished buffer” for that process step.
  • Stories must be minimal marketable features
  • To be marketable the feature needs to be large enough to be useful — probably larger than the teeny stories that take a couple days to build and seem to be best practice in Agile development today. A MMF may take weeks to build. But the important thing isn’t how long it takes to build, but that it be understandable and valuable to those who’ll receive it. To identify a MMF some folks ask the question “Would I announce it in my company’s product blog?” If it’s too tiny to mention, then it’s not a MMF.
  • To be lean, we’ll limit the number of stories we allow onto the board. A common formula is to add up all the members of the team in all roles and divide by two. All roles includes developers, analysts, user interfaced designers, testers, deployment people — anyone immediately responsible for getting features to market. For example, if team members total 20, we might limit the number of MMF-style stories on the board to 10.
  • Today developers have finished a story, and s they walk to the Kanban board to move it out of development, they notice their single buffer slot is full — and the “testing in progress” column is filled to its limit. What now? The developers talk to the testers. “We’re really struggling to keep up here. It’ll be till tomorrow morning before we can get some of these stories moved out.” “Hmm�” says a developer “Can we help test?” “Of course you can!” says the tester. “With your help we can get these cleared out by the end of the day.“ The tester grins “I just don’t want you validating a story you implemented.”
  • For the limits of the story process steps, the limit is often half the number of people that can perform the work for that phase of development. For instance if you have 6 developers, you might limit the development in progress column to 3. Now, this will force developers to work together on stories. I do find in practice that this may not work out for all teams — so I often see limits that equal the number of developers (or those that can perform the process step) or often 1.5 * the number of people in a role. Of course if you do this, it’ll raise the overall work in progress — and as you might expect, items will take longer to finish.
  • When a column in a Kanban board is full, we know that group is at capacity. We also know that if this keeps happening that that process step is likely where a bottleneck is.
  • If you’ve ever waited in line for the Pirates of the Caribbean in Disneyland you might remember signs along the way that say “Your wait time from here is 30 minutes” — something like that. Now you can post your own wait times on your Kanban board. At the bottom of your story queue post the average cycle time with wait time. It’ll say something like “Your wait time for a story here is approximately 18 days.” At the top of the queue post the average working cycle time. It might say “your wait time from here is 14 days.”
  • When you place focus on how quickly you can get functionality done, and have the ability to measure just that, then the estimates don’t much matter. In fact, many using a Kanban approach have simply stopped estimating at all. Yes story sizes vary, but being able to give a wait time plus or minus a few days is sufficient for many organizations’ concerns.
  • But, since there’s no development time-box in Kanban development, we’ll measure story-by-story how long they took to complete — the “cycle time” of the story.
  • Some do still estimate stories. Then use those estimates in conjunction with cycle time. Using a spreadsheet we can calculate the average cycle time for stories with a given estimate. If you do this, consider placing a handy chart next to your Kanban board showing estimate in one column, and wait times in adjacent columns. With this you’re answering the real question stakeholders are asking for when they get estimates: “when am I going to see this functionality in the software?”
  • If your stakeholders are like mine, they don’t want to know when they’re going to get this functionality, the want to know when they’re going to get all this functionality. I find that if I place stories into a spreadsheet with start and end dates, and calculate cycle time, if I select an arbitrary time period — say a two or three week time period — I can see how many stories where completed during this time period. For instance I might see the team finished 22 stories in 3 weeks — that’s about 7.3 stories per week. Given a backlog of 100 stories I can reasonably infer that it’ll take between 13 and 14 weeks (100/7.3). That’s yesterday’s weather for Kanban — at least the way I calculate it.
  • If I know that during three week time period there where 15 working days and that 5 developers worked the entire time, that’s 75 developer days. Knowing that lets me calculate the average number of developer days per story: 3.4 (75/22) — Which is darn close to pi — which makes me believe it has to be right. ;-) This number, 3.4, is what XP practitioners referred to as load factor.
  • Evaluation cycles, not development time-boxes
  • The only difference is the cycles aren’t used to plan and commit to stories any longer.
  • The daily standup or daily scrum meeting occurs as normal, but now it occurs in front of the Kanban board. Instead of the regular meeting ritual of checking in with each person to find out what they worked on yesterday and will work on today, the discussion revolves around the Kanban board and what will likely move on and off the board today, where “traffic” seems the heaviest, and what we could do to clear bottlenecks.
  • Reflect every few weeks
  • Lean practices help teams increase throughput. They don’t make developers type faster, rather they draw attention to bottlenecks that slow things down, help you see them and respond to them quicker. Using a Kanban board lets you easily visualize work in progress across different roles and lets you see when someone is taking on too much work simultaneously.
  • Demonstrate every few weeks
  • A task board as it’s commonly used in an agile approach can give you the visualization too. But, widening the task board to separate testing from development from acceptance or other process steps helps me better visualize where things are clogging up — helps me better diagnose problems. And, setting hard limits for process steps and respecting them really makes me deal with the problem in a way that dropping a pile of stories into a sprint or iteration didn’t. But, maybe it’s just me who’s lazy and avoids dealing with tough problems. I’m sure you’d never run into a situation where you and your team let lots of finished development work pile up waiting to be tested.
  • There’s no one as zealous as the newly converted There’s a lot of folks pretty excited about Kanban out there. I am too. Sometimes that zeal takes the form of telling people practicing common agile time-boxed development that they’re wrong. But, I guess I’m crusty enough to know that there’s lots of right ways to succeed and anyone who believes they’ve found the best ways is likely wrong. Don’t let those voicing opinions strongly for, or against, Kanban approaches stop you for digging in deeper and understanding the ideas behind it.
  • Yuval Yeret on 03 Jun 09
     
    one of the best articles about Kanban and its relation to Agile I've encountered so far - focusing on Feature development (not maintenance)
Yuval Yeret

Is Design Dead? - 0 views

www.martinfowler.com/...designDead.html

eng-practices-list

shared by Yuval Yeret on 10 Dec 14 - Cached
  • In its common usage, evolutionary design is a disaster. The design ends up being the aggregation of a bunch of ad-hoc tactical decisions, each of which makes the code harder to alter. In many ways you might argue this is no design, certainly it usually leads to a poor design. As Kent puts it, design is there to enable you to keep changing the software easily in the long term. As design deteriorates, so does your ability to make changes effectively. You have the state of software entropy, over time the design gets worse and worse. Not only does this make the software harder to change, it also makes bugs both easier to breed and harder to find and safely kill. This is the "code and fix" nightmare, where the bugs become exponentially more expensive to fix as the project goes on
  • the planned design approach has been around since the 70s, and lots of people have used it. It is better in many ways than code and fix evolutionary design. But it has some faults. The first fault is that it's impossible to think through all the issues that you need to deal with when you are programming. So it's inevitable that when programming you will find things that question the design. However if the designers are done, moved onto another project, what happens? The programmers start coding around the design and entropy sets in. Even if the designer isn't gone, it takes time to sort out the design issues, change the drawings, and then alter the code. There's usually a quicker fix and time pressure. Hence entropy (again).
  • One way to deal with changing requirements is to build flexibility into the design so that you can easily change it as the requirements change. However this requires insight into what kind of changes you expect. A design can be planned to deal with areas of volatility, but while that will help for foreseen requirements changes, it won't help (and can hurt) for unforeseen changes. So you have to understand the requirements well enough to separate the volatile areas, and my observation is that this is very hard. Now some of these requirements problems are due to not understanding requirements clearly enough. So a lot of people focus on requirements engineering processes to get better requirements in the hope that this will prevent the need to change the design later on. But even this direction is one that may not lead to a cure. Many unforeseen requirements changes occur due to changes in the business. Those can't be prevented, however careful your requirements engineering process.
  • ...6 more annotations...
  • The fundamental assumption underlying XP is that it is possible to flatten the change curve enough to make evolutionary design work. This flattening is both enabled by XP and exploited by XP. This is part of the coupling of the XP practices: specifically you can't do those parts of XP that exploit the flattened curve without doing those things that enable the flattening. This is a common source of the controversy over XP. Many people criticize the exploitation without understanding the enabling. Often the criticisms stem from critics' own experience where they didn't do the enabling practices that allow the exploiting practices to work. As a result they got burned and when they see XP they remember the fire.
  • XP's advice is that you not build flexible components and frameworks for the first case that needs that functionality. Let these structures grow as they are needed. If I want a Money class today that handles addition but not multiplication then I build only addition into the Money class. Even if I'm sure I'll need multiplication in the next iteration, and understand how to do it easily, and think it'll be really quick to do, I'll still leave it till that next iteration.
  • You don't want to spend effort adding new capability that won't be needed until a future iteration. And even if the cost is zero, you still don't want to add it because it increases the cost of modification even if it costs nothing to put in. However you can only sensibly behave this way when you are using XP, or a similar technique that lowers the cost of change.
  • My advice to XPers using patterns would be Invest time in learning about patterns Concentrate on when to apply the pattern (not too early) Concentrate on how to implement the pattern in its simplest form first, then add complexity later. If you put a pattern in, and later realize that it isn't pulling its weight - don't be afraid to take it out again.
  • begin by assessing what the likely architecture is. If you see a large amount of data with multiple users, go ahead and use a database from day 1. If you see complex business logic, put in a domain model. However in deference to the gods of YAGNI, when in doubt err on the side of simplicity. Also be ready to simplify your architecture as soon as you see that part of the architecture isn't adding anything.
  • XP design looks for the following skills A constant desire to keep code as clear and simple as possible Refactoring skills so you can confidently make improvements whenever you see the need. A good knowledge of patterns: not just the solutions but also appreciating when to use them and how to evolve into them. Designing with an eye to future changes, knowing that decisions taken now will have to be changed in the future. Knowing how to communicate the design to the people who need to understand it, using code, diagrams and above all: conversation.
Yuval Yeret

The Game of Team Culture - 1 views

www.infoq.com/...team-happiness-culture

twitterfavs agile change management infoq open agile adoption opt-in pull

shared by Yuval Yeret on 23 Mar 14 - No Cached
  • Yuval Yeret on 23 Mar 14
     
    How to Hack The Culture of Your Team (50min vid) http://t.co/GUB8tX0v3Y
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