Agile testing | 25
A performance assurance methodology
While there is clearly no ‘one size fits Performance Testing is the
all’ solution, the following proven execution of the tests described in
approach for performance assurance the Performance Test Plan. The goal
proved successful at EasyJet. of performance testing is the same
The Performance Test Strategy is as all testing: to ensure the system
an evolving document that underpins meets the stated requirements.
all performance testing activities and Performance testing can be conducted
defines an approach for performance across the development lifecycle. In
testing. The goals are to establish an agile development methodology
good-practice, to clarify the scope the development lifecycle is shorter
and goals of future performance and therefore the time window for
testing phases and to provide a solid performance testing will also
foundation and point of reference for be shorter.
any future tactical decisions. The Performance Test Report
The Performance Test Procedures is the main deliverable from the
document includes scripting performance testing activities. This
guidelines and describes how to test, documents all the tests executed,
how to prepare test data and how to how they were executed and the
log defects. This may be updated after detailed results. The report also lists
the performance testing is completed. the defects identified during the
The Performance Risk Assessment performance testing. This includes
is produced after the performance environmental, functional and
team has gained an understanding performance related defects.
of the code changes planned for Modelling activities are typically
the release. The objective of the cheaper than performance testing
assessment is to assign a risk to each as they don’t require large-scale test
element of the release and also to environments, costly automated test
provide a high-level estimate for man tools or even stable code. EasyJet’s
days and associated costs for the performance test environment
performance assurance activities. is significantly smaller than the
Typically this activity is carried out production system, therefore
by a more senior member of the modelling provides a cost-effective
performance team who has the approach to understanding what
experience to make judgements on the performance test results mean
what elements of the release are risky. for the production system. The
The risk is based on factors such results from the performance testing
as the expected demand for the are inputted into the capacity and
application and also how the changes performance model of the easyJet.
impact the architecture. This helps com platform in order to understand
to avoid testing for the sake of it the impact of the release on the
as everything is risk-based. It also production system resource utilisation
allows us to decide the priority and service performance. One
and execution order of tests in the weakness is that capacity modelling
Performance Test Plan. cannot determine whether soft
The Performance Test Plan bottlenecks such as database locks
defines the test environment and may occur.
provides further detail regarding ITIL describes the Capacity Plan as
the specific tests to be conducted. a document produced at predefined
Each test case should be referenced intervals which reports the current
against a risk in the Performance and anticipated future levels of
Risk Assessment. One key aim is to resource utilisation and service
ensure that performance testing is performance. Capacitas produces
Capacitas typically has a maximum of
not on the critical path for delivery a regular capacity plan for EasyJet.
two weeks to conduct performance
of the software. In this example This document is reissued, if required,
we were fortunate in that separate at the end of an agile release
testing within EasyJet. This has
functional testing was required for to determine the impact of the
required a greater emphasis on
all eighteen language translations software changes on the easyJet.com
planning performance tests to ensure while performance testing was only infrastructure capacity based on
that they are ‘right first time’
required to be conducted against the the capacity and performance
English version of the site. modelling work.
T.E.S.T | March 09 March 09 | T.E.S.T
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