Traceability in VS2010
Always an interesting question, how does traceability work in VS2010?
To often asked without any context, or only asked from a requirements perspective. Still way too open to answer in a tweet. So, a post to canalize those questions a little bit more…
[see the image below for the numbers]
you can take two directions when talking about traceability. The first is focused on “work”, the work items repository part of TFS [on the left side of the green dotted line]. with work related traceability we can answer questions like “did we completed all tasks for that requirement?” [for more see the red list]. Information which is very important for every roll in the Application Lifecycle. A tester want to know if he can start testing, so he want to see if the developer is ready. A project manager wants to plan the work. Developers want to know if designers are ready to start with a stabile set of needs… and many more. All work related information, and information which can be tracked/ traced by using work item and its repository.
VS2010 main capability for work related traceability are the TFS work item repository [see image below from MSDN] and linking of work items, setting up a hierarchy.
We can breakdown requirements, or user stories, in tasks. 
tasks that needs to be executed to get the requirement done. These tasks can have a parent-child relation [and other see Working with Link Types on MSDN]. Giving us the information we need in any kind of way, for example reports.
So far the work related traceability. The other kind of traceability is based on artifacts, things we make during the application lifecycle, I will call them ALM artifacts. ALM artifacts are used to create the solution/ application. For example the source, XAML and configuration files which make the solution. But, also the diagrams which we created to make a correct, consistent and good communicated application architecture, we use them to drill down from the needs to code. And also test cases belong to the things we make during the application lifecycle [I can imaging when you get confused now, test cases are within VS2010 work item types, but they definitely belong to the artifacts section].
Use case – user story what is the difference… I often use both [see this piece of MSDN documentation for modeling requirements]. User stories are work item types and use cases are ALM artifacts. So, they are a great bridge between the ‘work-world’ and ‘artifact-world’. The good thing is the capability of VS2010 to link diagrams, and other model elements to work items. [How to: Link Work Items to Model Elements], this give us the capability to create a trace.
From the description and diagrams of the requirements, the often called problem domain, we have to make a big jump into the solution domain.
Diagrams are created like the component diagram and layer diagrams visualizing the high level pieces of the solution with the dependency and interfaces between these components and layers. [used this image in this post; the modeling world].
It is also a big gap for traceability, to get this a little bit better a solution can be the replaying of scenarios written down in the user stories and drawn in activities as described in this post; VS2010 Modeling; Create Lifeline from Component.
A trace back from component/layer to requirement can be a link from model element to the user story work items in where he is used. Never did this, it’s a manual process and probably people will forget the links, maybe with some kind of notification this would be valuable…
An interesting VS2010 capability is the connection between the layer diagram and the sources. This makes a trace possible between the high level design and the sources. See image below.
Because test cases are work item types in VS2010 they can be connected to any other ALM artifact, giving us the possibility to connect for example test cases to use case diagrams. Easier to accomplish and to maintain is the connection with test tasks and corresponding user story. But this doesn’t answers questions like; “which code is touched by this test”. VS2010 answers this question with Test Impact, see “Determining Which Builds Have Bug Fixes, New Features, or Requirements”, “Recommending Tests to Run That are Affected by Code Changes” and “Developing Tests from a Model”.
Another interesting traceability scenario can be build with test case generation, see this ‘old’ Model Based Testing beta 1 video. [some more info on MBT can be read on Rob’s blog]
Next, 
all have a work related task. So, not only traceability within the two sections is possible also traceability between the two sections is possible. answering questions like; “which task created this line of code?”… creating this link / trace is a manual task but it can be controlled by a check-in policy.
So, when someone asks you the question; “what about traceability in VS2010?” you now can canalize this and guide him/ her to the real traceability question they want to have answered [and tell the solution]….
< probably more to come on this interesting topic, also because the extensibility model of the diagrams is powerful enough to create your own required traceability between artifacts with notifications and work item linking… very very interesting >
VS2010 Modeling; Create Lifeline from Component
From the VS2010 MSDN sequence diagram documentation…
Relationship to other diagrams
You can use UML sequence diagrams together with other diagrams in several ways.
Lifelines and types
The lifelines you draw in a sequence diagram can represent typical instances of the components or classes in your system. You can create lifelines from types, and types from lifelines, and show the types on UML class diagrams and UML component diagrams. For more information, see Classes and Lifelines.
Beside we can create lifelines from/for classes we also can create lifelines for/from components… which is actually a very interesting feature.
Context menu on a component shows the create lifeline option [not available when clicking on a part ]
After the creation of several lifelines, you can draw the interactions between the components. There isn’t functionality like the bi-directional method creation in the class-sequence diagram interaction for the component-sequence diagram. Kind of logic, a component only has interfaces.
Why would you want to do this, create sequence diagrams for components?
While the component diagram 
is a static view of your system the sequence diagram is dynamic, it visualizes the flow in your application, the sequence of actions that occur in the system. So, you could use sequence diagrams to validate your system, your component design. Take a scenario, a requirement scenario, and create a sequence of actions from in a sequence diagram 
. By doing this you create a kind of simulated behavior of the component structure, which you can check on correctness and consistency.
The scenarios used for this can be found in the use case diagrams 
, which describe the actions that take place on/in the system. Now describes a use case diagram not really a scenario, you better can use an activity diagram for that 
, which can be based on the use case diagram as a kind of use case realization. Now the interesting thing is, testers use activity diagrams to create test cases, they have specific technologies to extract the right amount and type of scenarios [see http://robkuijt.nl/index.php?entry=entry080423-135750 ], these scenarios we can use to validate our component design which actually closes the loop.
It would be even more interesting and powerful if we not only could link sequence and component diagrams but also use case and activity diagrams making notification when an activity changes and a scenario can’t be run anymore on the purposed component… hard to accomplish, but interesting, versioning would be hard…