Defects kill Sprint Planning

Burning down user stories sprint by sprint at a nice constant velocity is what we hope to be seeing on agile projects. What happens though if there are defects in the work we've delivered and we have to start planning the defect fixing as well as the new work? How should this situation be approached?

Firstly, don't deliver defects! Easy to say but we know that all teams deliver defects at some points. If you start getting a lot of defects back though it's a pretty sure sign that you have a false velocity - you're reporting work as done when it isn't really. It simply hasn't been tested enough. So the second point is that you have to face reality about the velocity of your team. Get the testing done and automated before you deliver the next set of stories.

All well and good but what about planning the next few sprints? How do we plan reliably now when we are not sure how much defect fixing we're going to have to do along side the new user stories. Here's one approach that seems to work... 2 velocities!

The overall velocity of the team is how many "points" the team burns down in a sprint. We want to ensure this is pretty constant, always assuming that the team stays constant and we're not carrying over too much work in progress at sprint boundaries (see here for a previous discussion of that problem). The second important velocity though is "effective velocity" - the amount of new client-required work that is burned down per sprint. This excludes work on defects (which means the higher velocity reported in sprints when you delivered the defects is balanced) and work on refactoring and process improvement (necessary but not what the client is paying for). You can see the effective velocity sprint by sprint by creating a new folder each sprint to contain just the new work completed/targeted).

Giving the team visibility of these metrics is important so they can see the impact of defects and also appreciate improvements when the effective velocity is restired.

Running xProcess with a console

It seems I missed out a vital piece of information in the previous blog - how do you create a shortcut that runs xProcess with a console. Actually it's pretty simple: add "- console" to the target command. So on a Windows machine the Target field of the shortcut should look something like this...

"C:\Program Files\Ivis\xProcess 2\xProcess\xprocess.exe" -console

Reporting and exporting from xProcess 2.9

A project I've been working with recently has been needing to get reports and data out of xProcess to integrate with other management reports. This hasn't proved as easy as I would have hoped with the product's standard reports, custom reports through BIRT, exporting and other options failing to give us what we needed. I decided to do some more experimenting with "UI Actions", which use OGNL to navigate over the data. Turns out this is a pretty good option with writing the required scripts being quite straightforward. The hardest thing turned out to be actually getting the export file which was a bit more of a hassle. I'm told all this will be great in v3 but for now here's my solution.

First you need to create a new Action in your process, and set it applicable to "Task" (or whatever type of object you want to report on) and "UI Action to "true". The only other crucial bit in this stage is writing the OGNL Expression. My script is below so you can always paste that in, see what it does and then change it!

We wanted to extract a set of key attributes of tasks (like dates and size) and display them in a spreadsheet.The script produces a set of comma-separated values (csv format). Unfortunately v2.9 doesn't give you an easy way to save this in a file. Instead the script outputs the values to the console (so you have to start xProcess with a console window). Once the output has been produced you then have to cut and paste the data into a csv file -- yes that's the "clonky" bit. Still it doesn't take a moment and you then have the data in a spreadsheet where you can mess with it to your heart's content. Brill!

All I want now is v3 so I can get this sort of report through a nice clean user interface. Here's the script...

"-- Output to console action - summarises task information --",

#categoryName ='Importance',
#category = #this.getProcess().getCategoryTypeByName(#categoryName),

#output='\n\nTabular output for: ' + getName() +'\n'+
'Name,'+
'Parent Task,'+
'Start,'+
'End,'+
'Target End,'+
#categoryName + (#category==null ? ' (WARNING - no such category)' : '') +','+
'Size (points),'+
'Estimate (person-hours),'+
'Actual/Planned (person-hours),'+
'Actual to date (person-hours),'+
'Closed?,'+
'Assigned to' +
'\n',

"-- First define the different functions for Leaf and Parent tasks --",

#leafOutput = :[
#output = #output +
name +','+
parent.name +','+
start +','+
end50 +','+
(targetEnd==null ? '' : targetEnd) +','+
(#cat=getCategoryInType(#category), #cat ==null ? '' : #cat.label) +','+
size + ','+
estimateOfEffort/60.0 +','+
bookedTime/60.0 +','+
bookedTimeToDateIncludingConfirmedTimeToday/60.0 +','+
closed,
getCurrentManualAssignments().{#output = #output + ',' + person.label},
#output = #output + '\n'
],

#parentOutput = :[
#output = #output +
'REST OF ' + name +','+
(parent==null ? '' : parent.name) +','+
start +','+
end50 +','+
(targetEnd==null ? '' : targetEnd) +','+
(#cat=getCategoryInType(#deliveryCategory), #cat ==null ? '' : #cat.label) +','+
(topDown ? (#result = size - sizeRolledUpFromChildren, #result>0 ? #result : 0) : '') + ','+
(topDown ? (#effort = estimateOfEffort - estimateOfEffortRolledUpFromChildren, #effort>0 ? #effort/60.0 : 0) : '') + ','+
bookedTime/60.0 +','+
bookedTimeToDateIncludingConfirmedTimeToday/60.0 +','+
closed,
getCurrentManualAssignments().{#output = #output + ',' + person.label},
#output = #output + '\n'
],

"-- Then process all the tasks, including the one selected --",

#tasks = getAllTasks(),
#tasks.add(#this),
#tasks.{
#this.isDesignatedAsParent() ? #parentOutput(#this): #leafOutput(#this)
},
#$sysout.println(#output),

"-- Inform the user where the output is",

#$dialog.informUser('Output to console: ' + getName(), 'The result of this action has been sent to the console.\nCut and paste the output into a Spreadsheet and use Data->Text to Columns... to create the table.\n\n'+
'Note: If you do not have a visible console, close xProcess and restart it from a command line window, or run xProcess with a console by adding "- console" to the target command. (E.g. on a Windows machine the Target field of the shortcut should look something like:\n\n"C:\\Program Files\\Ivis\\xProcess 2\\xProcess\\xprocess.exe" -console')

Note: one of the columns this scripts outputs is a category value ("Importance"). You could use the same pattern to display other relevant categories - "Target Delivery" for example if this was a category defined in your data.

How long should a Sprint be?

Generally I'd I'd say between 2 and 4 weeks. How long can the business leave the team alone to get on with what they've planned (the "no interruptions"rule) is one constraint. The other is how frequently do we need to update the release plan - we only really get feedback on velocity at sprint boundaries.

I've been working with a team recently where establishing a constant velocity has been very difficult. They are basically dealing with a large backlog of defects from previous iterations where they weren't using an agile process. Until this backlog is cleared it's largely academic how long the sprint is - they still get interrupted with a significant number of urgent defect fix tasks every week. Perhaps going to a weekly sprint, at least until this backlog is effectively cleared would help. That way the defects being worked on in that week would be known, with analysis only being done on new defect reports during the week. The sprint planning for the following week can then re-prioritize the work for the following week. This is an example of where the sprint needs to be short in order to handle rapidly changing priorities. However it also demonstrates the difficulty of trying to apply an agile process when a clear quality baseline has not yet been established.

In other circumstances I favour a longer sprint rather than a short one - at least 3 weeks. It gives the team a chance to establish it rhythm of delivering backlog items without the overheads of sprint planning and retrospectives interrupting.

Requirements, requirements, requirements

Is it possible to implement an agile project without overhauling your requirements process? I think not. The key economic benefits flow from agile methods ability to reduce "work in progress" compared to traditional methods [Anderson]. This means specifiers must take a much lighter approach to distant requirements and have much greater involvement, for example as "on-site customers" or product owners, in requirements currently being implemented.

[Anderson] Agile Management, Prentice-Hall (2003)

Availability - how much and who to?

When you're specifying your availability in xProcess there are 2 parts to the information required: when are you available? and to which projects? If you are wanting to change availability for people in your project from the assumed defaults (usually 8 hours each weekday), then here are a few hints to get you started.

The first part - your overall availability - can be specified for both organisations and for individuals Open an editor for either a person or organisation and you'll find (at the bottom of the editor pane) a tab labelled "Availability". This shows the availability records that have been defined. Each record has a from and to date ("..." means "forever" in this context, either in the past for the "from" date, or in the future for the "to" date). For each day of the week you can either specify a specific number of hours or inherit the hours specified on another person or organisation.

By default organisations at the top level (that is organisations with no parent organisation) are created with availability of 8 hours on Monday to Friday. Sub-organisations or persons within an organisation are created to inherit availability from their parent organisation. So for example public holidays can be defined by adding availability records at the top level and personal holidays defined on the individual person in the same way.

The second part of defining availability is to divide your time between one or more projects. When the Project Manager adds a resource to his team he must specify the percentage availability (default 100%) and the from and to dates for this person (defaults to the start and end of the project). To change the percentage of time available to any one project, hit the "Resources" button in the Project Manager perspective "Tools" panel, or open the project editor and go to the "Available Resources" tab. You can then select the relevant person and use the "Manage Project Availability for..." button. Again availability records can be added for a period specifying a percentage of the overall time the person is available on each day of the week. (The default in this case is 100% each day.)

Process patterns: what are "composites"?

The key to defining the task structure in a process definition is the task pattern. Task patterns consist of prototype tasks, optionally contained in a prototype project. Here's an example:

This is the task pattern for a "Feature" in the FDD process and it results in the creation of a set of subtasks and artifacts when the Feature pattern is "instantiated". This is quite a simple pattern and it doesn't include any composite tasks, which are structures to allow multiple tasks, optional tasks and iterations of tasks (repeated tasks that follow on one after the other). It is composites that allow arbitary process diagrams, drawn say using UML's activity diagram format, to be translated into xProcess processes. Here's an example of a task pattern, this time shown in the Hierarchy Diagram view, which does contain a composite. It's the "Feature Set" pattern from the same process.

The composite task in this example is called "Features: $Name$" (this is a pattern so the $Name$ will be substituted by the user supplied name when the pattern is instantiated). It contains a choice of 3 patterns: "Defect", "Feature" and "Task". Any of these patterns may be instantiated multiple times within the composite task.

Composite tasks are parent tasks, in other words they do (or will) contain child tasks, and they also define constraints on what type of child tasks can be created through the patterns they contain. In the latest version of xProcess composites can be instances (only one pattern can be instantiated in the composite), collections (an arbitrary number of patterns can be instantiated in them) or iterations (similar to collections but each pattern will be constrained to start after previously instantiated tasks have completed). Composites contain one or more patterns which define the options available when creating new tasks in the composite. In the example above, Defects, Features or Tasks can all be instantiated within the composite.

So the composite mechanism gives the Process Engineer the ability to define task patterns with loops, sequences and optional paths. More or less any pattern that can be represented in a flow chart or activity diagram can be created in an xProcess pattern by using composites. Composites go further though. Because of xProcess' support for top-down estimation, composites have their own estimates and resource requirements so that they can be scheduled even before the detailed decisions about how many tasks, iterations or options have been made.

To understand how these top-down estimates work in practice, see this blog article: Latest Patterns for Scrum which shows how the top-down estimate for a Sprint is used for scheduling resources, up to the point that all the backlog items have been created within it.

Footnote Question (for the techies among you!):
Are all parent tasks also composites as well as vice versa?
Well firstly all composites are parent tasks. Even if they as yet contain no child tasks they are classified as parent tasks because they allow task patterns to be instantiated in them. On the other hand parent tasks are only composites if they contain a set of patterns. This set defines the patterns that can be instantiated in the composite /parent task. So a parent task without such a set of patterns is not a composite and (in version 2.x) any non-hidden task pattern maybe instantiated in it.
[Note in version 3 this behaviour is likely to be changed, effectively removing any distinction between parents and composites. If the parent task does not contain any patterns, no patterns will be able to be instantiated in it. This will allow Process Engineers to create project patterns where, for example, certain tasks have a fixed set of children which cannot be added to.]