Estimation Games
Estimation is one of the interfaces between the the technical
domain and the management and commercial domains
People estimate, not methods or tools
There are tensions
Estimation Games
1. Reverse Doubling
2. Double and Add Some
3. Guess the number I’m thinking of
4. Double Dummy Spit
5. X Plus
6. Spanish Inquisition
7. What are they Prepared to Pay?
8. Gotcha
9. Back to the Wall and Drip Feed
10. Smoke and Mirrors
11. False Precision
1. Double and Add Some
1. Estimate
2. Double your estimate
3. Add some
4. Present to manager
5. Manager halves your estimate
6. You still have some, you win!
2. Reverse Doubling
1. Manager tells client estimate for delivery
2. Manager then tells team they have half the time
(excellent for setting the scene for further games when developer delivery date is
missed)
3. Guess the number I’m thinking of
Manager:
‘Hi <developer>. How long will it take to finish those extra screens?’Developer:
’Um, about six weeks, maybe more…’Manager:
WHAT!!??, That long??, You’re joking yes?Developer:
‘Oh!, Sorry, maybe four weeks?Manager:
‘
Four Weeks!, I don’t think <boss> is going to like that when she hears about that. (See No 5. X Plus)Developer:
OK, I’ll do it in three weeksManager wins
4. Double Dummy Spit
Manager:
‘So, its been three weeks – are the screens done?’Developer:
’Er, not quite…’Manager:
‘@@##xxx%%%!!! Not finished!!, What can I tell <boss>, you‘ve let me down, …and performance appraisals are coming up’Developer:
‘Oh!, Sorry, …but I’ve been working 12 hours a day, seven days a week. Sorry.’Manager:
‘
Well, we all make mistakes. So how much longer do you need?’Developer:
‘Another two weeks?’Manager:
TWO MORE WEEKS!!??, @@###xxx%%%.’5. X Plus
Manager:
‘Look, I’m sorry but we only have four weeks to deliver, but <very senior boss> has demanded it by then.6. Spanish Inquisition
In meeting to discuss innocuous topic, before the meeting ends:
Manager:
“Oh yes, before we go, <developer> they’ve
asked for eight more screens, how long will it
take to produce them?”
All turn to look expectantly at <developer>
<developer>
“ Um, about six weeks?”
This is an extension of
Reverse Doubling
:
1. Manager estimates project will take £10M
2. Manager deliberately reduces the estimate to an acceptable level,say £4M,
to get the work
3. Manager then uses
Gotcha
(next game) to recover the remaining £6M
using either as scope creep or unclear requirements
8. Gotcha
Studies show that gamblers will continue to gamble if given occasional small wins
– throwing good money after bad.
Client has spent £4M on the new system. Do they write off the investment or
put in another £2M to complete it?
Later: Client has spent £6M on the new system….
Client:
‘Hello Manager, will my project be delivered next week aspromised? After all you have been telling me its going well and the £4m has now been spent.
Manager:
’Well. I have some good news and some bad news.’Client:
‘Uh huh, give me the bad news’Manager:
‘The bad news is that the system won’t be ready next week.’Client:
‘
@@###xxx%%%.’<insert double dummy spit>
Manager:
‘Wait. The good news is that things are going well and with another £1m the system will be ready in two months.10. Smoke and Mirrors/Blinding with Science
Client:
‘How long will the revised Foobar system take?’PM:
’Let’s see, 22 external inputs, 4 Logical Internal files, 5 concatenated enquiries, Hm… That’s 8 by 12 minus risk adjustment factor of 3.2, add Rayleigh Curve simulation, subtract because of global warming… 35 weeks!’11. False Precision
Client:
‘How long will the revised Foobar system take?’PM:
’Let’s see, 22.1 external inputs, 4.8 Logical Internal files, 5.001concatenated enquiries, Hm, thayts 8.02 by 24.003 plus 12.4 minus risk adjustment factor, add the Rayleigh curve simulation, subtract because of global warming…. 35 weeks, two days and four
hours, plus or minus an hour!’
Client:
‘Wow, impressive – you really know your stuff!’O X F O R D
S O F T W A R E E N G I N E E R I N G
L I M I T E D
9 Spinners Court, 53 West End, Witney, Oxfordshire OX28 1NH www.osel.co.uk [email protected] Tel. +44 (0) 1993 700878
