interlude-case-study-tree-rev-6x - Scaling Software Agility

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Nov 21, 2013 (3 years and 8 months ago)

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Agile Requirements.

Interlude


Case Study


2009, Leffingwell, LLC. All Rights Reserved.

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Interlude

Case Study: Tendril Residential
Energy Ecosystem

Interlude

Table of Contents

Introduction

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2

Background for the Case Study

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................................
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.......

2

System Context Diagram

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3

Agile Requirements.

Interlude


Case Study


2009, Leffingwell, LLC. All Rights Reserved.

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Introduction

Managing

requirements in a
significant agile development project is a complex task, and the
requirements concepts, practices, and artifacts have to scale to the task at hand.

W
e intr
oduce
a case study
, Tendril Networks, Inc., as an example

of a real company that is
actively applying
agile requirements methods i
n
the development of an innovative, and complex
hardware and software system.
As the book progresses, we’ll
use some

real arti
facts
from this
case study to help illustrate the practices we are describing.

Background for the Case Study

The green revolution is upon
us
in many and varied fields. For our case study, we have selected a
Boulder, Colorado, company that has become one of

the leaders in the green energy field. Tendril
Networks,
Inc. has embraced the emerging technologies of the

Smart Grid


movement as their
basis for the development of new energy saving products for commercial and home use.
The

following paragraphs
are
ex
cerpted and adapted from a Tendril White Paper that may be found on
their website,
at
www.TendrilInc.com
.

The nation’s electricity grid was built and regulated for reliability and ubiquitous availability.
Those wer
e admirable goals for 20
th

century infrastructure, but as we move into the 21
st

century,
electricity and energy needs have gone beyond mere reliability and ubiquity. We now need to
reduce/eliminate global warming

and to use energy efficiency to
increase ou
r energy
independence
. Enter the Smart Grid.

The term Smart Grid covers a range of initiatives, including upgrades to:



T
he long
-
haul transmission grid to enable movement of renewable and non
-
renewable energy to places that can consume them



T
he short
-
haul
distribution grids so that they are more efficient with energy
delivery



E
lectricity meters with two
-
way communications infrastructure between the
customer and the generator/provider

As it is currently defined, the Smart Grid only solves part of the problem
. It is meant to reach
consumer’s homes, but the existing infrastructure falls short, ending at the meter. The Tendril
technology infrastructure moves inside the home and completes the Smart Grid in the new
Information Age.

By using networking technology,
the end
-
consuming devices can know:



When environmental friendliness is high



When grid reliability is low



When the price is cheap



When and where energy is needed more or less, and the overall consumption
“profile’ that each consumer desires

Agile Requirements.

Interlude


Case Study


2009, Leffingwell, LLC. All Rights Reserved.

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Similarly, the p
oints between the generation and consuming devices can know:



Where demand is high versus low



Where outages may have occurred and the nature of the outage



Whether meters ought to be connected or disconnected



Where renewable supply is and how to route it to
the right demand locations



When the long
-
haul or short
-
haul grids are inefficient (and why)

Of the many Smart Grid components, the consumer
-
oriented elements deserve as much attention
as the alternatives. A
ft
er all, it is only when consumers
use

renewable energy,
or cheap energy, or
when distributed generation in their homes can be effectively sold, that our nation will achieve
the results it seeks


true 21
st

century energy efficiency.

As a contributing part of the Smart Grid solutions, Tendril
offers a comprehensive line of
residential energy management products, collectively known as the Tendril Residential Energy
Ecosystem (TREE). These products combine a significant array of
firmware

and software
engineering challenges and are the focal point

of a large
-
scale series of agile development efforts
both on the
firmware

side and the software side. As this book progresses, we will be examining
various artifacts of these engineering projects as part of our case study.

In some cases, it will also be n
ecessary to look at agile lean requirements that fall outside the
practices used by Tendril. Never fear, these practices will also be discussed with other artifacts of
other case studies.

System
Context
Diagram

Tendril offers a variety of products that fur
ther the Smart Grid initiative. For our purposes, we
will only consider a representative selection of the product offerings
, Tendril Vantage
. This
subset will typify many of the
agile development
techniques and challenges that are used for the
entire range

of product offerings.

Tendril Vantage is a browser
-
based Internet application that provides consumers with the tools
and

information they need to better understand, manage
,

and control their energy consumption
and each of the

smart devices in their home.
With Tendril Vantage
,

users can register their home,
electric appliances
,

and

devices. Users can also set rules, personal alerts and notifications, track
their consumption in real
-
time,

review historical usage patterns
,

and compare their household
energy e
xpenditure against other homes

in their area with similar demographics.


Agile Requirements.

Interlude


Case Study


2009, Leffingwell, LLC. All Rights Reserved.

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Figure
1

Tendril Vantage
s
implified
s
ystem
d
iagram

As Figure
1

illustrates, the
Vantage product

consists of three major subsystems:

1.

The electric utility

2.

The energy management servers

3.

The consumer’s home and devices

We will
describe

the use of agile
requirements
techniques
in support of development of
the
Tendril
Vantage product as well as other products in the Tendril product line
.

We will

start

by
using the case study in the context of the next chapter, User Stories
.