Rob Kuijt's Testing Blog
Model-Based Testing is not "Only Fun" anymore.... 
Saturday, June 20, 2009, 02:09 PM - ALM, Quality, Testing, TMap®, Fun
Posted by Rob Kuijt
For several years now, Model-Based Testing is mainly used within the (technical) development processes. In the Black Box testing community it was still "just a theory", and in my case: fun to play with. Today is different! I'm completely into Model-Based Testing nowadays. MBT turned, for Black Box testers, into serious business!

Wikipedia:
Model-Based Testing is software testing in which test cases are derived in whole or in part from a model that describes some (usually functional) aspects of the system under test (SUT).


For quite some years I'm working with a tool called COVER. Initially COVER was build to help lazy testers, like me, to avoid boring manual activities…and it worked! Using this tool I could easily amaze my surrounding with stunning Speed and Quality. Especially deriving test cases from formal specifications like pseudo code or activity diagrams was fun to do; instead of "solving a boring puzzle" time, it was done in seconds (as a matter of speaking). However, most of the testers in my surrounding didn't recognize the ease of this way of working (or were not lazy enough?) so COVER didn't have much users.

Today is different. The attention for Model-Based Testing is growing rapidly. Previously, when a project had to make test cases, it was accepted that it was done manually and, everybody knew, it should take quite some time.
Today the budgets are lowered...What to do?...Less productivity?
My suggestion: When you've less money to spent, be creative to get the same results!

First Model then Test!


Model-Based Testing is a nice example of creative thinking!
Within a few months the relatively unknown possibilities of Model-Based Testing tools became very popular for Black Box testers within Sogeti. Especially the collaboration-part (designers working together with testers) of Model-Based testing is an eye opener. Everybody knows that it is smart to find defects as early as possible, but it is very difficult to motivate teams to perform good design inspections. Now MBT tools like COVER can do a big part of those intensive inspections, because using the models for generating test cases will directly show the defects in those models in a very early phase of the project! And beside that, it generates a big part of the test cases!

So, when the Designers create models that COVER understands, projects will perform Better, Faster and Cheaper! ....and it works!
Some (early) successes from our proof-of-concepts and implementations:
  • The amount of time needed for creating test cases dropped 50% (and sometimes more);
  • The maintenance of the (regression) test cases became in average 70-80% cheaper;
  • And maybe most important: We have proved to find defects much earlier than the project did manually!

Collaboration will change the world of testers!
Using MBT is in fact collaborating within the Application Lifecycle [ALM] supported by standardization and automation. Many defects, found in functional testing, have their origin in misinterpretations and assumptions of the requirements and/or specifications. The early usage (generating test cases) of formal models, just after or during the design phase, will create a much more solid base for software coding. For the testers this will mean less and less defects, so besides the generated test cases, the improved quality of the software will also fasten the test process.
(PS. When both software and test cases are generated from the same models, be sure that the test objective is clear!)

This industrialization can’t be stopped anymore. The time of creating most test cases by hand has had its peak. Of course, not all test cases can be generated, and also manual testing itself will never disappear, but handcrafted test cases will be less and less common practice. The work of Black Box testers will, in my opinion, shift in two directions: 1) Earlier in the life cycle: joined modeling and helping and supporting development to find defects as early as possible (Master Test Plan consultancy), or 2) the coming market End-to-End testing: the importance of complete chains of applications is growing rapidly. End-to-End Testing will become a separate specialism.

Examples
Back to Model-Based Testing: To give an idea what type of models can be used, and how test cases are generated, I've made a some slides (with examples) about the Sogeti MBT tool: COVER. Look for yourself if MBT will affect your work!

It did affect mine!
;-)
Rob Kuijt
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Visual Studio Team System 2010 - Episode 4: Quality Check 
Friday, April 24, 2009, 10:04 AM - ALM, Quality, Testing, TMap®, Rosario
Posted by Rob Kuijt
In this episode I will discuss the different practices around the Quality Check in order to do this important check for ALM as efficient and effective as possible.

Previous episodes:
Visual Studio Team System 2010 - Episode 1: A Focus on Testing
Visual Studio Team System 2010 - Episode 2: No Risk No Test
Visual Studio Team System 2010 - Episode 3: The Lifecycle

In the last episode Clemens talked about the support VSTS2010 will give on the collaboration at artifact level. Different roles in the lifecycle work together on artifacts. Each of them adds their knowledge, vision and ideas to the solution from their view point. These artifacts are accessible by every role in every phase of the project, adding value throughout the lifecycle. People are enabled to collaborate, making applications together, and not only by telling what they are doing but most important by working seamless together on the application.


TMap® Quality Check
A subsequent measure for increasing the quality of the developed artifacts is an evaluation activity: for instance the review.

The review is a method of improving the quality of an artifact by evaluating the work against the requirements and/or guidelines and subjecting it to peer review.

The review on the requirements and/or design can be carried out as a static test activity before the coding starts.
In the review, the following points can be checked, independently of the set requirements:
1. Has the artifact been realized in accordance with the assignment? For example, are the requirements laid down in the technical design realized correctly, completely and demonstrably?
2. Does the artifact meet the following criteria: internally consistent, meeting standards and norms and representing the best possible solution? ‘Best possible solution’ means the ‘best solution’ that could be found within the given preconditions, such as time and finance.
3. Does the artifact contribute to the project and architecture aims? Is the artifact consistent with other, related artifacts (consistency across the board)?
4. Is the artifact suitable for use in the next phase of the development?

Why?
Like testing, the Quality Check is a measure to provide insight into the quality of delivered products and the related risks when taken into the next phase of the lifecycle. If the quality is inadequate timely measures can be taken, such as rework by the designers. However, there is never an unlimited quantity of resources and time. In theory it is important to relate the Quality Check effort to the expected risks. A pragmatic approach to determine the Quality Check effort is to look at some past projects and answer the question:

"How many defects, detected in Acceptance Tests, could have been found much earlier, if we had done a Quality Check? (According to the above points)"
In my experience 10-20% of the defects could have been found much earlier in the lifecycle when the Quality Check was done properly. And because defects in the Acceptance Test are quite expensive, you only have to find 1 or 2 serious defects in the Quality Check to make it economic worthwhile. So my strong recommendation is:

7 Hints and tips
1. Performing a good Quality Check is a kind of inborn specialization. Find a person who is good in recognizing texts with high potential risk on assumptions and or interpretation errors. In other words: find a pencil-pushing, nit-picky quality geek!
;-) Most professional testers are proud to have these qualifications.

2. Before checking an artifact: What is the quality of its source? Is the source of the AUC (Artifact Under Check) ready? authorized? stable? If not, consider to do also a check on the source of the artifact to quantify the possible changes in the (near) future,

3. If a previous version of the artifact is available, and the quality of that version is known: make use of a so called Comparison Tool to find and check the differences. AND! Check always the consistency of the “change register”, especially when the “change register” is used in the next phase to implement the changes.

4. Combine the Quality Check with the estimation activity for the next phase. If the estimation is done by another person, let them work together!

5. Use a checklist as a reference! For your own protection, a checklist prevents that too much attention is paid to the use of standards and correct spelling or even to these aspects alone (This can be a cause of friction among the various people involved.) Partly owing to the diversity of design techniques and information sources that, it is not possible to create one general checklist per artifact type. Therefore, checklists should be created specific to the situation per organization and per project. Of course you can use examples like Testing Requirements or Testing Use Cases as a start for the creating of your checklist.

6. Make always clear what checks you will perform. By communicating your checklist you can prevent a lot of misunderstandings on later findings.

7. Audi alteram partem (hear the other side). Don't report on findings/defects without a fair hearing in which the author of the artifact is given the opportunity to respond to the "accusations" against his work.

Collaborate
For some, it is very tempting to do a review in their own silo: Get the stuff to check, find as much as defects as possible, receive applause for the prevented damage and do that over and over again……
Wrong! Don’t be a Scrooge! (see my blog: "Does Scrooge exist?") An essential part of the Quality Check is the Learning Cycle. By performing Quality Checks the quality of future AUC’s (Artifacts Under Check) must grow. So collaborate with the designer, information analyst or whoever made that artifact, and get your applause on the better quality of artifacts instead on the number of defects.

In the next episode Clemens will explain how the tools support the Quality Check, as well as the collaboration around it, to get the optimum results.




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Visual Studio Team System 2010 – Episode 2: No Risk No Test  
Tuesday, February 10, 2009, 08:08 PM - ALM, Quality, Testing, TMap®, Rosario
Posted by Rob Kuijt
In episode 1, Clemens introduced the focus of Visual Studio Team System 2010 on the collaborative effort between the tester and the other roles in the application lifecycle. In this second episode I will start with a short introduction on testing.

Testing is not an aim in itself! Testing is, in fact, a balancing act. What risks must be covered, what results are to be delivered and how much time and money can be spend, based on rational and economic grounds?

The right test strategy will balance among risks and costs .


Testing supplies insight in the difference between the actual and the required status of an object. Where quality is roughly to be described as 'meeting the requirements and expectations', testing delivers information on the quality.

In this, there is no difference for developers who are testing, specialist testers during system testing or generalist testers during the final acceptance test. Choosing the right test strategy is a joined effort between every tester and the other roles in the application lifecycle. This collaboration is needed because, beside insight in the business risks, much (technical and test) knowledge is needed to find the most important defects as early as possible at the lowest price.

The collaboration doesn't stop after choosing the best test strategy. After designing the test cases, also test execution must be organized as a joined effort. Collaboration between the different roles in the application lifecycle is not self-evident. By nature, it looks like developers and testers don't (want to) understand each other. Having this attitude, it is difficult to find out you need each other to deliver software of good quality.

...don’t (want to) understand each other.


The consequence of this virtual (and sometimes real) wall is calamitous for quality. Many bugs arise by doing wrong assumptions and interpretations of the, in generally, unclear specifications and requirements. Reporting, analyzing and resolving these bugs take a lot of time, especially when they prove to be not reproducible or wrong.

An Example: After a development project of 5 man year, testing is done by a team of generalist testers. With much enthusiasm the test team executes the test cases they designed during the building of the system. After 3 months the verdict is given: Negative release advice, because of (8) blocking and (22) big defects, the test team gives the advice NOT to go into production. As you may understand this was a big disappointment for both the project team as the business department. A taskforce was established to keep the delay (damage) in control. After the defect analysis the general feeling became better, after filtering the test faults (20%), the functional wishes (20%) and changes (not passed through to the testers; 30%) the repair costs were approximately 200 hours ( for the remaining 30%). In fact the development team had done a great job. Better communication from both sides, before and during test execution, probably had made the verdict a, celebration worthy, positive release advice. Much, much better than this cold shower!

The above paragraphs show that the collaboration between the tester and developer is important for success. If the collaboration between the different roles in the application lifecycle is not actively stimulated and facilitated, the proverbial wall will arise.

In the next episode Clemens shows us how Visual Studio Team System 2010 will support and stimulate this collaboration...

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[ALM] & Business Continuity 
Sunday, July 27, 2008, 08:38 AM - ALM, Quality, Testing, TMap®, Rosario
Posted by Rob Kuijt
Application Lifecycle Management [ALM] should ensure that an organization experiences an improved "business as usual" in the event of the implementation of new and/or changed functionality. Other (older) industries can give assurance, so the ICT industry should follow (soon?). This article will, I hope, give some next steps towards adulthood, by giving [ALM] directions how to prevent costly or even lethal disasters caused by bugs.

Business Continuity has for [ALM] two viewpoints:
  • [ALM] is part of the interdisciplinary concept, called Business Continuity Planning (BCP), used to create and validate a practiced logistical plan for how an organization will recover and restore partially or completely interrupted critical function(s) within a predetermined time after a disaster or extended disruption (see wikipedia for more information),
  • [ALM] must give assurance that developing and/or changing applications won't create disasters or extended disruptions! (I won't explain what software bugs can accomplish...).


In this entry I will give some thoughts concerning the second viewpoint:
How to prevent a major disruption caused by the implementation of a new or changed application?

Of Course, the Acceptance Test is very important in our "battle" to prevent the worst to happen. But, as I stated earlier in my article "What's in the Box?", the Acceptance Test alone is not enough! Based on the Business Risks (Business Driven Test Management *) the Master Test strategy in [ALM] must contain at least the following three pillars:
  1. Finding Bugs AEAP (As Early As Possibly)
  2. Bug Prevention by Testing Requirements and Use Cases
  3. Gathering and Analyzing data to do Business Continuity Predictions

*) Business Driven Test Management gives client grip on test process, uses client language, delivers appropriate test coverage on right spot and makes test results visible for client (see TMap.net for more information)

Pillar 1: Finding Bugs AEAP (As Early As Possibly)
Finding bugs as early as possible prevents changes in the software in the last phases of a project.
Recently I participated in an (early) evaluation of an organisation, where the strategy of finding bugs as early as possible was implemented for the complete software engineering department by choosing the Quality Levels, tuning the Test Coverage of the successive test levels and introducing Learning Cycles. They had geat results!
See two earlier articles on this topic:

Problem solved? No, not yet, by diminishing the bugs, it became clear that the number of late change requests and/or wishes for extension of the functionality were disturbing the implementation of the applications. So it became obvious that the next pillar became more important...

Pillar 2: Bug Prevention by Testing Requirements and Use Cases.
If software development is based on inaccurate requirements, then despite well written code, the software will be unsatisfactory. No doubt that the users do want to change the application before it is implemented. Changing an application in the last stages of a project will generate huge risks.


Testing Requirements
Testing the requirements in the early stages of the project will minimize the changes on the application just before implementation. To give the testing of requirements a head start, I derived a checklist from the article "An Early Start to Testing: How to Test Requirements (Suzanne Robertson)"
  1. Does each requirement have a quality measure that can be used to test whether any solution meets the requirement?
  2. Does the specification contain a definition of the meaning of every essential subject matter term within the specification?
  3. Is every reference to a defined term consistent with its definition?
  4. Is the context of the requirements wide enough to cover everything we need to understand?
  5. Have we asked the stakeholders about conscious, unconscious and undreamed of requirements? Can you show that a modeling effort has taken place to discover the unconscious requirements? Can you demonstrate that brainstorming or similar efforts taken place to find the undreamed of requirements?
  6. Is every requirement in the specification relevant to this system?
  7. Does the specification contain solutions posturing as requirements?
  8. Is the stakeholder value defined for each requirement?
  9. Is each requirement uniquely identifiable?
  10. Is each requirement tagged to all parts of the system where it is used? For any change to requirements, can you identify all parts of the system where this change has an effect?


Testing Use Cases
After the requirements are tested they evolve in a functional model (for instance Use Cases) of the required application. To Test the Use Cases you can use the checklist I derived from the article: "Use Cases and Testing (Lee Copeland)"
1)Syntax Testing
  • Complete:
    • Are all use case definition fields filled in? Do we really know what the words mean?
    • Are all of the steps required to implement the use case included?
    • Are all of the ways that things could go right identified and handled properly? Have all combinations been considered?
    • Are all of the ways that things could go wrong identified and handled properly? Have all combinations been considered?
  • Correct:
    • Is the use case name the primary actor's goal expressed as an active verb phrase?
    • Is the use case described at the appropriate black box/white box level?
    • Are the preconditions mandatory? Can they be guaranteed by the system?
    • Does the failed end condition protect the interests of all the stakeholders?
    • Does the success end condition satisfy the interests of all the stakeholders?
    • Does the main success scenario run from the trigger to the delivery of the success end condition?
    • Is the sequence of action steps correct?
    • Is each step stated in the present tense with an active verb as a goal that moves the process forward?
    • Is it clear where and why alternate scenarios depart from the main scenario?
    • Are design decisions (GUI, Database, …) omitted from the use case?
    • Are the use case "generalization," "include," and "extend" relationships used to their fullest extent but used correctly?
  • Consistent:
    • Can the system actually deliver the specified goals?
2) Domain Expert Testing
  • Complete:
    • Are all actors identified? Can you identify a specific person who will play the role of each actor?
    • Is this everything that needs to be developed?
    • Are all external system trigger conditions handled?
    • Have all the words that suggest incompleteness ("some," "etc."…) been removed?
  • Correct:
    • Is this what you really want? Is this all you really want? Is this more than you really want?
  • Consistent:
    • When we build this system according to these use cases, will you be able to determine that we have succeeded?
    • Can the system described actually be built?
3) Traceability Testing
  • Complete:
    • Do the use cases form a story that unfolds from highest to lowest levels?
    • Is there a context-setting, highest-level use case at the outermost design scope for each primary actor?
  • Correct:
    • Are all the system's functional requirements reflected in the use cases?
    • Are all the information sources listed?
  • Consistent:
    • Do the use cases define all the functionality within the scope of the system and nothing outside the scope?
    • Can we trace each use case back to its requirement(s)?
    • Can we trace each use case forward to its class, sequence, and/or state-transition diagrams?


Pillar 3: Gathering Data and Analyzing Trends to do Business Continuity Predictions
It is NOT possible to predict Business Continuity based on the testing process of the concerning project only. It is important to get a better foundation for the decision to implement a changed or new application. In the Rosario TAP we are doing some research for Gathering Data and Analyzing Trends to do Business Continuity Predictions from three viewpoints:
  1. Fault Detection Trends
  2. Change Control Trends (Changes in Requirements, Specifications, LOC’s,...)
  3. Project Control Trends (Estimations, Budget, Overtime,...)

We’ve just started on this topic, so I will keep you posted in later entries.

Collaboration is a critical success factor in preventing a major disruption caused by the implementation of a new or changed application! All parties within [ALM] have to work together in creating good test coverage from the early until the last phases of the projects. I am sure that only when the Quality Levels, Learning Cycles and Metrics are in place, a good Business Continuity risk advice can be given to ensure that an organization experiences an improved "business as usual" in the event of the implementation of new and/or changed functionality.

Rob

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Finding bugs AEAP (As Early As Possibly) 
Saturday, June 7, 2008, 07:56 PM - ALM, Quality, Testing, TMap®
Posted by Rob Kuijt
Analyzing and fixing a bug is, without doubt, a loss of time. And the later the bug is found, the greater are the losses. Finding bugs AEAP (As Early As Possibly) becomes more and more important, especially in the complex systems we make nowadays. So, let's join the knowledge of the Developer, the Tester and the Designer and tackle this challenge!


Of course we can train the individual team members to test their own work....but, I know from my own experience, you can be blind for your own short comings.

In the Application Life Cycle we should stimulate Developers, Testers and Designers to work together in the challenge to Find Bugs AEAP (As Early As Possibly). Join their knowledge and they will accomplish better systems in less time!
For instance, let's look into the creating of Unit Test cases. The Unit Test mechanism is great, but if you don't know anything about test coverage it's almost impossible to get the advantages you want.
Let me give an example how the Developer, the Testers and the Designers can work together....

Case
Let’s say a Developer must create a component that contains the following decisions:
if C1 and (C2 or not C3)
then
        if C5 or C4
        then
                "Result_1"
        else
                “Result_2"
        end if
else
        if C3 and C4
        then
                "Result_2"
        else
                "Result_3"
        end if
end if


We want to create Unit Test cases which will Find the Bugs AEAP....That's why we must choose for the best test coverage: Modified Condition/Decision Coverage (MC/DC)


Modified Condition/Decision Coverage
Every point of entry and exit in the program has been invoked at least once, every condition in a decision in the program has taken on all possible outcomes at least once, and each condition has been shown to affect that decision outcome independently. A condition is shown to affect a decision’s outcome independently by varying just that decision while holding fixed all other possible conditions. (wikipedia.org)


It is not easy to create the test cases for the test coverage MC/DC, especially if you want a minimum amount of test cases. Here the Tester comes into the play. With the help of TMap® test specification techniques, he/she creates the (logical) test cases. In this case the Tester delivers the Developer the following 7 (logical) MC/DC test cases.



Depending on the risks, and with the help of Equivalence classes and Boundary value analysis, the physical test cases are derived.
Now, the Developer can start building the test cases into his/her component.

So, by joining their knowledge, the Developer and Tester did create, for this phase in the life cycle, the best test coverage to Find Bugs AEAP . The effect of collaboration can even be greater if the Unit Test cases, before implementing in the code, are reviewed by the Designer.

Reviewing the test cases gives the Designer insight in the assumptions and interpretations of the Developer and Tester.

Finding Bugs during this review is the ultimate AEAP!!!

Creating these test cases manually is, even for experienced testers, pretty difficult. Within Sogeti we use a tool (I made) for this work. (The generation of the test cases of this example took me 5 minutes).



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