Dashboard homepage with classic editor.
50 questions based on Scrum Foundation 2018 learning objectives.
Dashboard homepage with classic editor.
50 questions based on Scrum Foundation 2018 learning objectives.
Old posts will be here soon !!
30.9.2017: Old posts are now back on line with little reformatting and typo corrections.
Success stories and surveys support agile software development. In addition to anecdotal evidence there are little hard figures to guide our decision making. Here cumulative business value charts are used to describe the impact of agile and traditional choices to the bottom line. Focus is on visualizing the economic impact of individual agile practices and assumptions of their costs and profits.
A chart describing the cumulative earnings as a function of time is a basic tool for optimizing the return of investment, ROI. The line is higher all the time if we have multiple deliveries. It is still better if the more profitable increments are deployed the first. This advantage in time-to-market is clear also in the surveys. Double the results in half of the time assumes that earlier deliveries have business value and that the additional cost of more deliveries is small.
The cost of change must be small if we proceed empirically and feedback directs our product and development process. Customers pay these changes when they create more value than the costs of delaying and implementing the the changes.
Risks are an integral part of any design. In software development we do not commonly know what the users actually need and how we use new technologies that create the results. The cone of uncertainty is high. Reports of more than hundred-fold effort differences are common. Sales, savings and profit estimates are so inaccurate that it is quite common to ignore them altogether.
Traditional mass production uses specialized lowest costs work force, rigid processes and invests in tools. It locally optimizes the cost of the tasks that workers do and is often blind about the required administrative burden.
Traditional and agile approaches have different assumptions of the relative costs of the parts of software development. Agile assumes high risks, high integration and collaboration needs, low predictability and low cost of change.
Example driven development is the best name to cover acceptance test driven development, behavior driven development and specification by example approaches. The concepts of acceptance test, testing and a tester have been defined long ago. I have found that changing their meaning is difficult. Even when we talk about test driven development we have to spend a lot of effort to explain that it is not done after programming and not by the separate testers.The same happens if we talk about specifications.
The old school uses user stories as a new way of writing specifications, which could be then send to a separate development team. Collaborative design is not happening as it should. Though I like the idea of programming with natural languages, I think that they are too abstract and too prone to interpretations. Examples are a good way to explain things unambiguously and in a way that both the users and programmers see useful.
Behavior is something that programmers talk about, but for users that might not be as clear as examples. With example driven development I want to emphasize collaborative design where users and developers work together using examples to clarify how users interact with computer programs to achieve business benefits that pay the return on investment.
Traditionally we have specifications, tests and code written to different purposes. They should not just be consistent but the same. In agile tests are specifications and in behavior driven development code is moving closer to the tests. The ultimate goal might be that we have only one description of the program that can be understood by both the users and the compilers. That is one goal of visual programming.
The lack of programmers has been tried to be solved by moving the work to users. This approach has not been very successful because building large programs requires a lot of logical thinking and solutions to huge amounts of details. Software designers are not endangered species but programmers might be if the abstraction level of programming goes up.
In this list I have a lean and management focus:
Hope, Jeremy: “Beyond Budgeting: How Managers Can Break Free from the Annual Performance Trap”.
Denning, Stephen: “The Leader’s Guide to Storytelling: Mastering the Art and Discipline of Business Narrative (J-B US non-Franchise Leadership)”.
Denning, Stephen: “Radical Management”.
Reinertsen, Donald G.: “The Principles of Product Development Flow: Second Generation Lean Product Development”.
Reinertsen, Donald G.: “Managing the Design Factory: A Product Developers Tool Kit”.
Goldratt, Eliyahu M.: “Theory of Constraints”.
Ries, Eric: “The Lean Startup: How Constant Innovation Creates Radically Successful Businesses”.
Gojko Adzic: “Specification by Example: How Successful Teams Deliver the Right Software”.
Fowler, Martin:”Domain Specific Languages (Addison-Wesley Signature)”.
Big front-end designs are bad, because they do not match the reality. The devils are really in the details. However, the cost of changes is considered too high and the illusion of predictability makes us close our eyes on reality.
In Scrum we say that we should focus on infrastructure and architecture in the first Sprints. Decisions about our software development environment, tools and architectures are not easily reversible. The situation is much worse in the construction business. If we are building a bridge or a tower of Eiffel we can’t start it again from the beginning if the base is not strong enough.
The case is not that bad in software development. We use software instead of electronic circuits just because it is easier to change software than hardware.We need to have appropriate engineering practices to change Kent Beck’s famous cost curve. Extreme programming contains many practices that are needed to make the code easy to change. In addition to these we need solid architectural principles and rigorous attitude to quality.PowerPoint architectures outlined at the first Sprints are not good enough. We need executable architectures and extensive testing with highest priory business functionality to make sure that the quality attributes, non-functional requirements, are OK, before we continue deeper.We don’t stop to that. We require that the architectures are easy to change. Ease of refactoring and testing can be achieved with known design patterns.
My colleague has written a provocative blog entry about the current situation of agility.Actually, we are promoting our new course: Agile Engineering Practices, which can be used as a part of Certified Scrum Developer curriculum.
My talk in Scum Gathering Amsterdam is now visible. See more about visual software design with themes and epics The place: 10:00 – 11:00am on Tuesday, November 16 in Foyer
Synopsis: We have issues like user stories, themes, epics, UI mockups, business rules and acceptance tests that are used in creating our understanding of what to do and how. We groom product backlogs and have Sprint planning meetings and design tasks in Sprint backlogs. This IdeaCamp session pursues to tell us how to put these all together in real life projects.
The slides and result flip charts are now available at SlideShare. I like especially the idea of drawing users’ value stream with epics shown by one of the groups in the idea camp.
I bought some lean&agile books to read during my summer holiday. The list is not complete because I have already read quite many of them. I got Mike Cohn’s new Scrum book freely from the publisher. Thanks about that.
Craig Larman: “Scaling Lean and Agile Development: Thinking and Organizational Tools for Large-Scale Scrum: Successful Large, Multisite and Offshore Products with Large-scale Scrum (Agile Software Development)”.
Lisa Crispin: “Agile Testing: A Practical Guide for Testers and Agile Teams (Addison-Wesley Signature)”.
Mary Poppendieck: “Leading Lean Software Development: Results are Not the Point (Addison-Wesley Signature)”
Roman Pichler: “Agile Product Management with Scrum: Creating Products That Customers Love (Addison-Wesley Signature)”.
Lyssa Adkins: “Coaching Agile Teams: A Companion for ScrumMasters, Agile Coaches, and Project Managers in Transition (Addison-Wesley Signature Series (Cohn))”.
David J Anderson: “Kanban”.
Jason Fried: “ReWork: Change the Way You Work Forever”.
James Coplien: “Lean Architecture: for Agile Software Development”.
Daniel H. Pink: “Drive: The Surprising Truth About What Motivates Us”.
Chip Heath: “Switch: How to Change Things When Change is Hard”.
A short history of waterfall
As experienced people remember the eve of software development was agile. Waterfall emerged because the prevailing management thinking embraced it. There was a quest for more rigor and predictability and we started to talk about software engineering which would improve our quality and productivity. More planning was an obvious solution when plans were failing.
When the systems grew the developers began to specialize, which was based on the prevailing mass production paradigm. Functional organizations were the norm everywhere. Because it was difficult to find skillful programmers, the tasks were divided so that cheaper and available labor could be used for defining, testing and documenting. Promotions to project managers enabled the traditional corporate ladder hierarchy.
Outsourcing was tried to solve the software crisis by decreasing the unit cost of the huge amount of work that was required for writing each single line of code only to find out that the distribution created another layer of complexity.
Massive process guides tried to catch every possible view of software development to make it predictable and repeatable. 80s was the era of methodologies. After that we got quality initiatives like CMM which created a quagmire of documentation and turf wars between them. It was still very difficult to tell how to create software because we have so many variations of it and its development. You had to write either something that is right and so generic that it does not help or something that must be applied or something which fits only to certain kinds of software development.
CHAOS reports told that the majority of software development project were not successful. Success factors were extracted and we found that the requirements and capability of making decisions are the keys to success. Systems thinking explains the failure of old straightforward initiatives. Specialization, outsourcing and rigorous processes answered well to one visible view of software development but they did not optimize the whole. Big front-end planning did not create better plans because the plans were frozen prematurely without appropriate testing and feedback.
In the 70s computers were less powerful than they are today. The programmer wrote the code to a paper based on which punch cards where created. Then the cards were read, compiled and finally executed. If anything went wrong the programmer had to make corrections and try again. The length of the development cycles might have been several hours if not days. Barry Boehm’s famous paper published in 1981 about software development economics was based on studies of the projects earlier than that. So it is natural that it concluded that the cost of a change is so huge that errors should be prevented at practically any cost. Reviews and careful table testing were the ways to prevent errors.
Waterfall was born due to the management paradigms but it is useful to consider the feasibility of modern iterative development using the technology of the past. Essential practices like continuous integration and automated testing were difficult but not outright impossible in all of the projects. Programming cycle times have not prevented agility after the punch card. The “mythical man-month” of Fred Brooks was written in 1975 but this was unfortunately not enough to change the history of software development.
My colleague at Tieturi, Arto Santala, has written a series of three blog entries about unit testing in EJB 3 environment. It is in Finnish but you might get the point through the code examples without our language.As an idea unit testing has been known and used for decades but examples in blogosphere focus on simple situations instead of complex cases of real life. When we do unit and acceptance testing in industrial scale, we need to go deeper considerations about maintainability and performance of the test harness.