www.uni-stuttgart.de

Cyber-Physical Systems

Stefan Wagner !!

RCoSE 2014 Hyderabad, India

3 June 2014

ScrumA Process Proposal

for

@prof_wagnerst #scrumcps

My Company Practices Agile

yes

no 16

84

Source: 7th Annual State of Agile Development Survey (2013)

in % of respondents

Agile Development in general, but mostly Scrum is more and more prevalent in information systems development !http://www.versionone.com/pdf/7th-Annual-State-of-Agile-Development-Survey.pdf

Which Agile Methods Do You Use?

Scrum

Kanban

Lean

XP 7

11

15

40

in % of respondents

Source: The State of Scrum (2013)

And Scrum clearly dominates !https://www.scrumalliance.org/scrum/media/ScrumAllianceMedia/Files%20and%20PDFs/State%20of%20Scrum/2013-State-of-Scrum-Report_062713_final.pdf

Cyber-physical systems (CPS) are physical and engineered systems whose operations are monitored, coordinated, controlled and integrated by a computing and communication core.

Rajkumar et al.

Picture: © Siemens

Agile system engineering practices have matured for software projects while hardware system engineering continues to embrace classical development techniques.

Huang et al.

And we depend in CPS development also on hardware development http://pixabay.com/p-329155/?no_redirect

So how can we use Scrum for building CPS?

General Idea

Design Sprint Planning

Design Sprint Backlog

Product Backlog

Hardware Sprint PlanningHardware Sprint Backlog

Design Sprint Review

Design Sprint Retrospective

Potentially shippable software/ hardware design increment

Potentially shippable product increment

Hardware Sprint Review

Hardware Sprint Retrospective

e.g. Hardware NFA

Design Sprint Execution Daily

Scrum

Daily Scrum

Hardware Sprint Execution

Agile Release Train

Product Backlog

Potential Release

CPS Challenges and SolutionsSoftware/hardware co-design Major design team,

agile release train

Robustness, safety, security, real-time

Early design, SW-/HW-in-the-loop tests

Architecture Global design

Sensor and mobile networks Agile release train

Model-based dev. Everything’s a model!

V&V, certification Early and continuous V&V, certification?

The agile release train ensures consistent interfaces

Example

Fitness TrackerSmartphone App

Smart wristlet

Cloud & Web Interface

The wristlet tracks the movements of the person, connects via Bluetooth to the smartphone for syncing the movement data and shows a movement score. With the synced information, it also vibrates when more movement is needed, and it suggests activity via the small screen. The smartphone app connects to the cloud service via Internet. The cloud service captures all the movement data and personal configurations. It also allows social functions such as comparing one’s results with those of friends.

As a user, I want to be able to see my movement data in numerical and diagrammatical form on my smartphone.

As a user, I want to be able to connect my wristlet to my smartphone.

Two example user stories

Product Backlog

Potential Release

Design Sprint: Wristlet (CAD, RapidHDL, C)

Design Sprint: Smartphone App (Java)

Design Sprint: Smartphone App (Java)

Design Sprint: Wristlet (CAD, RapidHDL, C)

Design Sprint: Smartphone App (Java)

Hardware Sprint: Wristlet FPGA Prototype

90-days cadence with 30-day sprints

Variations

Safety-Critical Components

Depends on domain-specific standards

Example: MC/DC Coverage • Strong focus on early and continuous testing anyway • Include in definition of done

We need specific care, of course. We also will need to conform to domain-specific standards, such as DO-178B and C, ISO 26262, IEC 61508. They all either require or recommend MC/DC coverage.

Hardware Design Language

Rapid HDL

VHDL

SystemC

CAD

Doesn’t really matter. Might be chosen based on prior experience, company standards etc. Only requirement is that it is simulated (and of course that we can build hardware using it).

Next Steps

1. Student project in collaboration with electrical engineers

2. Industrial case studies

Picture: http://pixabay.com/de/schritt-schritte-pfad-richtung-275929/

The major challenge is to bring non-software parts into the continuous feedback cycle.

Besides safety-critical stuff and certification complex stacks of cloud services