Modeling Kanban Scheduling in Systems of Systems
Alexey Tregubov, Jo Ann Lane
2
Outline Problem statement Research approach: Kanban process Overview of KSS Network Benefits of KSS Simulation model Simulation results
Health care example Complex example
Future work
3
Problem statement In SoS environments the following problems observed:
Lack of visibility: What is going on at the project level? What is the current status of SoS capabilities?
How to expedite certain urgent capabilities? Everything is critical but nothing is done Every constituent team establish their own
priorities
4
Research approach: Kanban process Kanban in manufacturing industry:
It is a system to control the logistical supply/demand chain. Toyota,1953.
Kanban as part of lean concept: “Pull” instead of “push” in demand Kanban is part of Just in time (JIT) delivery approach
Kanban in a software engineering (as a process): Visualized work flow – kanban boards Limit WIP Feedback and collaboration to improve the flow
Kanban in System of System environments: Kanban scheduling in work prioritization Value based work prioritization based on SoS capabilities,
balanced with single system needs Visualization
5
Overview of KSS Network
6
Benefits of using KSS Eliminate waste
Minimize context switching Limit work in progress
Make process more visible and transparent Kanban boards
Increased value delivered earlier Value-based work prioritization
Reduce governance overhead
7
Cost context switching in multitasking
1 project 2 project 3 project 4 project 5 project0.00
20.00
40.00
60.00
80.00
100.00
120.00
Percent of Time on Project
8
Simulation model
Discrete event simulation: Inputs:
Event scenario: a sequence of events that describes how network evolves over course of their execution
Team configuration: structure of teams, resource/specialties allocation
Simulation configuration: stop condition Outputs:
Sequence of network states Analysis: various indicators of effectiveness
9
Simulation model: Kanban scheduling
All work items (WI) prioritized according to their business value
Every WI has a class of service: Standard, Important, Date Certain, Critical Expedite
Limiting work in progress: work in progress is never interrupted unless new work has a Critical class of service work is suspended by prerequisites
Visualization: kanban boards for each team.
10
Health care example of KSS Network
11
Example: capabilities to requirements to products
12
Example: capabilities to requirements to products
Value = 60
Value = 20
Value = 10
Value = 10
13
Example: capabilities to requirements to products
Value = 60
Value = 20
Value = 10
Value = 10
2050
20
40
10
10
14
Example: network structure & scenario
15
Example: outputs
16
Example: simple scenarioValue:
0 5 10 15 20 25 30 350.00
200.00
400.00
600.00
800.00
1000.00
1200.00
random kss
Time
17
Example 2: complex scenario
10 teams (20 members each) + system engineering team.
20 new capabilities at start. Each capability unfolds into 30 requirements
on average Each requirement unfolds into 9 tasks on
average. Each tasks takes 3-15 days. There are 5 expedite tasks that cause blocked
work (blocked tasks)
18
Example 2: value comparison
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 72 75 780
10000
20000
30000
40000
50000
60000
KSS
Value-neutral (random selec-tion)
LIFO
Time
Value
19
Example 2: number of suspended tasks
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 72 75 780
5
10
15
20
25
30
35
KSS
Value-neutral (random selection)
LIFO
Time
Number of Suspended
Tasks
20
Example 2: work items in progress
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 72 75 780
50
100
150
200
250KSS
Value-neutral (random selec-tion)
LIFO
Time
WIP
21
Example 2: total time spent (schedule)
KSS Value-neutral (random selection) LIFO61
62
63
64
65
66
67
68
69
70
71
Total schedule (person-days)
22
Example 2: total effort
KSS Value-neutral (random selection) LIFO440
460
480
500
520
540
560
580
600
Total effort (days)
Effort requiredif there are interruptions
23
Example 2: context switching
KSS Value-neutral (random selection) LIFO0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
Effort on context switching(person-days)
24
Conclusion: future work
Pilot the Kanban scheduling with several organizations
Fine-tune the simulator using empirical data and organizations’ feedback
Scale up the cases we run through the simulator
Refine and calibrate cost models
25
Questions & answers
26
References Waldner, Jean-Baptiste (September 1992). Principles of Computer-Integrated
Manufacturing. London: John Wiley. pp. 128–132. ISBN 0-471-93450-X. "Kanban". Random House Dictionary. Dictionary.com. 2011. Retrieved April 12,
2011. Ohno, Taiichi (June 1988). Toyota Production System - beyond large-scale
production. Productivity Press. p. 29. ISBN 0-915299-14-3. Richard Turner, Jo Ann Lane, Goal-question-Kanban: Applying Lean Concepts
to Coordinate Multi-level Systems Engineering in Large Enterprises, Procedia Computer Science, Volume 16, 2013, Pages 512-521, ISSN 1877-0509, (http://www.sciencedirect.com/science/article/pii/S1877050913000550)
Torgeir Dingsøyr, Sridhar Nerur, VenuGopal Balijepally, Nils Brede Moe, A decade of agile methodologies: Towards explaining agile software development, Journal of Systems and Software, Volume 85, Issue 6, June 2012, Pages 1213-1221, ISSN 0164-1212, (http://www.sciencedirect.com/science/article/pii/S0164121212000532)
Woods D. Why Lean And Agile Go Together : [Digital document], (http://www.forbes.com/2010/01/11/software-lean-manufacturing-technology-cio-network-agile.html). Verified on 7/7/2013.
Gerald Weinberg, Quality Software Management: Vol1. Systems Thinking. 1991
Top Related