Hi600 u02_prj_man_dorsey

1. THE SINKING OF THE VASA
TAKEN FROM:
RICHARD E. FAIRLEY, MARY JANE WILLSHIRE, IEEE SOFTWARE JOURNAL,
MARCH 2003,
‘WHY THE VASA SANK:10 PROBLEMS AND SOME ANTIDOTES FOR
SOFTWARE PROJECTS’
The Vasa, salvaged and restored in Stockholm

2. SINKING OF THE VASA
 Aug 10, 1628, Sweden’s most spectacular ship
ever, the Vasa, departed on its maiden voyage
and capsized a mile from shore, killing 53 sailors
 Why?

3. FACTS:
 King Gustav commissioned the building of
4 ships in 1625:
2 smaller ships, 108 ft keel
2 larger ships, 135 foot keel

4. FACTS
 Ship to be based on
 existing nautical technology
 proven production methods
 To be built quickly
 Construction started in early 1626 on the Vasa,
as a small, traditional ship
 Construction ended in late1628, with the Vasa
being delivered as a large, ‘innovative’ ship

5. FACTS:
 Confusing changes to the requirements
were introduced:
2 smaller ships now to be 120 ft keel (from
108), to carry more armaments (war w/
Denmark)
Then, Vasa was ordered to have 135 foot keel,
to host 2 gun decks
 Problem: 111 foot keel already laid
 No expertise in Sweden for 2 gun decks
 Builders decided to extend 111 ft keel, rather than
lay new 135 ft keel

6. FACTS:
 Confusing changes to the requirements were introduced:
 Vasa built 1.5’ wider than originally planned to accommodate extra
gun deck, but only in upper part of ship. This raised the center of
gravity considerably.
 Presence of 2 gun decks did not provide enough room for ballast

7. VASA CROSS-SECTION

8. FACT – ORIGINAL ARMAMENTURE
INCLUDED THIRTY-TWO “24
POUNDERS”
 36 ‘24 pounders’
 24 ‘12 pounders’
 8 ‘48 pounders’
 10 other smaller guns
 64 ‘24 pounders’
New Specs Final Specs
Final
Implementatio
n: 48 ‘24
Pounders’

9. VASA - STERN

10. FACTS:
 Henrik Hyberttson, chief shipbuilder,
became ill and died in 1627, midway
through construction
 He took most of the tacit knowledge of the
‘big picture’ with him to the grave, leaving
no documentation.
 Project planning and communication was
weak, lacking detailed specs, milestones,
workplans.
 400 people in 5 different groups performed
uncoordinated work

11. FACTS:
 There were no techniques for calculating center of
gravity and other aspects of performance and stability.
 Captains had to ‘feel’ the ship and make intuitive
adjustments.
 Pre-launch stability test consisted of 30 men running across
the deck from port to starboard.
 Modern simulations have shown that, because of its
haphazard construction, the Vasa would capsize at a
heeling angle of only 10 degrees, and a wind of 4 knots. *
*4 knots is not enough wind to unfurl a flag on a flag post. It basically means that
you can feel wind on exposed skin.

12. FACTS:
 The test was halted due to the violent rocking
of the ship.
 Not much room for ballast below deck
 Shipbuilder was unaware of the results of the
test; ‘If only the King were here’…
 The King demanded that the ship set sail by
July 25, lest the parties responsible be subject
to disgrace.

13. FACT
 The Vasa Sank.

14. PROBLEMS/ANTIDOTES
Excessive schedule pressure
 Objective estimates
 More resources
 Better resources
 Prioritized requirements
 Phased releases
Changing needs
 Iterative development
 Change control/baseline management

15. PROBLEMS/ANTIDOTES
Lack of technical specifications
 Development of initial specifications
 Event-driven updating of specifications
 Accountability
Lack of a documented project plan
 Periodic and event-driven updating
 Baseline management of the project plan
 Accountability (designated project manager)

16. PROBLEMS/ANTIDOTES
Excessive and secondary innovations
 Baseline control
 Impact analysis
 Continuous risk management
 A designated software architect
Requirements creep
 Initial requirements baseline
 Baseline management
 Risk management
 A designated software architect

17. PROBLEMS & ANTIDOTES
Lack of scientific methods
 Prototyping
 Incremental development
 Technical performance measurement
Ignoring the obvious
 Back-of-the-envelope calculations
 Assimilation of lessons learned
Unethical behavior
 Ethical work environments and work cultures
 Personal adherence to a code of ethics

18. THE END
(Or “Slutet” in Swedish)