Subject: Scheduling unpleasantness

From: Iljitsch van Beijnum <[email-masked]>
Date: Mon, 24 Mar 2008 15:41:02 +0100

Finally back at the office today...

While it is a fact of life that sessions clash at IETF meetings, I  
must say that Philadelphia has been especially bad in this regard.  
Does anyone else have the same experience?

If it wasn't just me, I think it's time to look at the scheduling  
algorithm in some detail, because from where I'm sitting, it's broken.  
My interests are mainly in the internet area + some routing and  
congestion related issues. The int area pretty much had two sessions  
the whole week except on friday, so I guess that avoiding overlap  
there is unavoidable. But there were instances where there were five  
of int, tsv, rtg and irtf routing/congestion at the same time.

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---

From: Bill Manning <[email-masked]>
Date: Mon, 24 Mar 2008 08:57:55 -0700

one has to schedule unpleasentness, since there is so much of it.

-- 
--bill

Opinions expressed may not even be mine by the time you read them, and
certainly don't reflect those of any other entity (legal or otherwise).

---

From: "Eric Gray" <[email-masked]>
Date: Mon, 24 Mar 2008 11:10:53 -0500

Iljitsch,

	I'm not sure that I would say that Philadelphia was
worse than most meetings, but it may have been from your
perspective.

	This sort of scheduling problem is very well known
to be NP hard and trying to meet the scheduling conflict 
matrix for 1500 to 2500 people would make the "N" large.

	I've heard that it is already very difficult to find 
a scheduling solution that satisfies the conflict matrix of 
just the ADs and WG chairs for the meetings they have to 
attend (not taking into account the meetings they want to 
attend as well - where, in some cases, "want to attend" 
means they may miss something important fo their own WG or 
Area if they can't go).

	Given that the conflicts of ADs and WG chairs are -
for the most part - the result of fairly focused interests,
it is likely that there is still some degree of freedom in
the range of acceptable scheduling solutions.  This means
that it might be possible to further refine final results
to accomodate other people - except that there is not a
(well defined) mechanism for gathering input from others.

	And there are probably problems with defining a means
to collect input from others. A few that I can think of off
the top of my head are:

o	people might see this as some form of guarantee;
o	you can't reliably expect people to differentiate
	what they "want" from what they "need" when asking
	for this kind of input;
o	there are always going to be those people who are
	their companies only IETF "representative" and who
	have (as a result) an agenda lacking in focus;
o	the longer you wait in collecting input, the larger
	"N" gets, and the harder the problem is to solve in
	any reasonable amount of time;
o	I'm not sure how much super-computer time the IETF
	can afford to consume to solve a problem of this
	nature;
o	etc.

	One approach to address at least these issues is to
consider (perhaps as an experiment) adding a check-list of
meetings people would like to attend to the registration
form, taking the first "P" people to register (or however
many have registered by some date in advance) and applying
their input to attempt to refine the solution for only the
areas where there are degrees of freedom in the range of
solutions already determined from AD and WG chair input (we 
can't bump a WG chair out of being able to attend a WG 
meeting).  We would also have to make it clear that this 
would only be used for the very limited scope implied, for
those people who elect to give input.

	This could be an optional portion of the registration
- reached perhaps by clicking on a button for those people
who want to try taking advantage of it.

	Of course, a simpler alternative would be to try to 
stick to a fixed schedule.  That way, it is more difficult
to find yourself in an unresolved scheduling conflict at
one meeting when you have not had the problem previously.
If you're trying to stick to a fixed schedule, you only 
have to solve the scheduling problem for the meetings that
need to be inserted or moved for some reason.

--
Eric Gray
Principal Engineer
Ericsson  

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On 
> Behalf Of Iljitsch van Beijnum
> Sent: Monday, March 24, 2008 10:41 AM
> To: IETF Discussion
> Subject: Scheduling unpleasantness
>

---

From: Jari Arkko <[email-masked]>
Date: Mon, 24 Mar 2008 19:44:54 +0200

Iljitsch,

Tell me about it... I had more than one WGs of my own meeting at the
same time (6MAN and MEXT), triple booked on slots like the Tuesday
morning slot where we had MEXT, V6OPS, and RRG at the same time, etc.
INT has for years generally met (at least!) twice on every slot, and the
ADs typically can go only to their own WGs. In this IETF I had 2 slots
where my WG was not meeting. And in addition to the official agenda
there is typically a fair number of private meetings and some bar BOFs,
even during the day.

But in general, I think this is due to an impossible number of conflicts
to satisfy, rather than some failure in running the scheduling algorithm
to get the optimal result. Basically, given a limited number of slots
and a number of interested folks/presenters/chairs/ADs that cause
conflict lists to be created, I'm not sure we can do any better. Of
course, I don't know this for a fact; its just my experience that when a
new conflict arises in my WGs, the alternate scheduling suggestions tend
to have either equal or worse conflicts. If anyone is interested in
checking the schedules for optimality, that might be an interesting
exercise, though.

But other than algorithm improvements, making the scheduling better
would mean either lengthening the IETF week, lengthening the days, or
reducing the number of people who need to be in several WGs/areas. The
last one is an argument for getting more new people into chair and
editor positions, as opposed to relying on the well known super experts
that come with the need-to-be-in-that-other-wg-too baggage...

Jari

---

From: Brian Dickson <[email-masked]>
Date: Mon, 24 Mar 2008 18:15:59 -0400

> worse than most meetings, but it may have been from your

Iljitsch is far from alone, just the earliest and most vocal of us. :-)

> matrix for 1500 to 2500 people would make the "N" large.

Universities have been doing this successfully for class scheduling for 
many years
with great success. I would not necessarily classify it as "hard".

> 	what they "want" from what they "need" when asking

There are two key constituents, which it cannot be denied meet the 
"must" category.
WG chairs, and presenters.

I was faced with pre-conference scheduling conflicts for two presentations.
They thankfully ended up not conflicting, because the WG's were both 
split in two,
and my presentation schedule was split across the two time slots.

However, both halves of both WGs were scheduled to be simultaneous - WG-A1
and WG-B1 together, and WG-A2 and WG-B2 together.

I would say some close attention could be paid to the subject matter, 
and to determine
that there is in fact a natural overlap between these groups in particular:

IDR
SIDR
RRG
6MAN
V6OPS

(As they all have to do with global routing, advances in routing 
protocols, and new routing
technologies, each with unavoidable overlap in subject matter and 
participants.)

> form, 

There is certainly a very reliable basis for tracking "interest", and in 
particular "co-interest indices",
based on the "blue sheets".

Here's how to do it:
Track across multiple meetings, using anonymized identifiers, to show 
which WGs have significant overlap.
Similarly, break up into several "pools", those with minimal overlap.

Those should ideally form a set of N pools, where each pool needs to be 
coordinated, but where
no coordination inter-pool is needed. The pools correspond to "tracks", 
in track-oriented
conference-speak.

The first step is to acknowledge that there is a problem, and to make a 
commitment to addressing
the problem in a systematic fashion.

Brian Dickson

---

From: "Clint Chaplin" <[email-masked]>
Date: Mon, 24 Mar 2008 15:34:14 -0700

>  with great success. I would not necessarily classify it as "hard".
Define "successfully".

Having been locked out of more than one course because of scheduling
conflicts, I would suggest that "successfully" to the university may
not be perceived as "successfully" to the students.

Which, come to think of it, is the same position IETF finds itself in:
replace "university" with "IETF" and "students" with "attendees".

-- 
Clint (JOATMON) Chaplin
Principal Engineer
Corporate Standardization (US)
SISA
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---

From: Mark Andrews <[email-masked]>
Date: Tue, 25 Mar 2008 11:18:37 +1100

> >  many years with great success. I would not necessarily classify it as
> > "hard".
> >
> Define "successfully".
> 

	I agree.  I had to get special dispensation to miss a lecture
	each week for one course.  I also had to arrange for someone
	to take notes for me for that lecture.  Definitely sub-optimal.

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: [email-masked]
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From: Harald Tveit Alvestrand <[email-masked]>
Date: Tue, 25 Mar 2008 04:58:05 +0100

Diving into solutions space....

The WG scheduling tool has 3 lists of "groups to avoid conflicts with", 
1st, 2nd and 3rd priority.

I don't know if these are visible to anyone but the requesting WG Chair, 
but they're listed on the confirmation notice from the tool; I've made 
it a practice to copy them to the WG I schedule, and modify the list 
according to comments.

So I'd ask:

Were the meetings you had problems with listed in each others' conflicts 
list?
  - If not, it's a problem at the "data input" level.
  - If yes, it's a problem at the "conflicts resolutions" level.

The solution to the problem depends on where the problem is, of course.

(Note: Conflicts at some level are unavoidable. Even bad conflicts. But 
if we can give the secretariat good data to figure out what those 
conflicts are, we're one step ahead.)

                      Harald

---

From: "John Loughney" <[email-masked]>
Date: Mon, 24 Mar 2008 21:35:12 -0700

Harald,

Even a simpler solution.  If you (meaning Iljitsch) had serious conflicts,
then let the WG chairs know about these conficts.  They may may not on the
WG Chairs' radars.  That has happened to me, where WG members were
overlapping with groups that I was unaware of.

John

---

From: Iljitsch van Beijnum <[email-masked]>
Date: Tue, 25 Mar 2008 14:22:05 +0100

On 25 mrt 2008, at 4:58, Harald Tveit Alvestrand wrote:

> The WG scheduling tool has 3 lists of "groups to avoid conflicts  
> with", 1st, 2nd and 3rd priority.

> I don't know if these are visible to anyone but the requesting WG  
> Chair, but they're listed on the confirmation notice from the tool;  
> I've made it a practice to copy them to the WG I schedule, and  
> modify the list according to comments.

> Were the meetings you had problems with listed in each others'  
> conflicts list?

I don't know, I haven't seen these lists.

Apparently the scheduling situation wasn't (much) worse for most  
others. In my case, I had huge overlap on monday and tuesday and then  
pretty much nothing of interest happened on wednesday and thursday.

Although it's useful to have wg chair input on scheduling issues, I  
don't think that's sufficient. What we need is to see which wgs have  
overlapping constituencies. We actually do have this data already, in  
the form of the blue sheets. But obviously it's not usable in its  
current, analog form.

So I'm offering to build an online version of the blue sheets so in  
the future, it will be easy to determine which wgs attract the same  
people and overlap can be avoided more effectively.

---

From: Bill Manning <[email-masked]>
Date: Tue, 25 Mar 2008 06:46:19 -0700

> people and overlap can be avoided more effectively.

	as someone who has been the victim of contact/email 
	harvesting off the "analog" blue sheets, i'll point out
	that when i attend an ietf, i -never- sign them anymore.
	
	so go forth, make your tool.  and please publish your 
	data protection/privacy policies and remedies when said 
	policies are breached.

	at that time, i'll consider the value add for me to avail
	myself of your tool.

--bill

---

From: Marshall Eubanks <[email-masked]>
Date: Tue, 25 Mar 2008 10:08:02 -0400

> 	that when i attend an ietf, i -never- sign them anymore.

By whom ? At the meeting ? They are never exposed to the public.

Regards
Marshall

---

From: Joe Abley <[email-masked]>
Date: Tue, 25 Mar 2008 10:17:36 -0400

> By whom ? At the meeting ? They are never exposed to the public.

I thought the standard solution to Bill's problem was to write  
illegibly :-)

Joe

---

From: Bill Manning <[email-masked]>
Date: Tue, 25 Mar 2008 11:55:51 -0700

> By whom ? At the meeting ? They are never exposed to the public.

	er... yes at the meeting, by folks sitting in the 
	seats.  since IETF mtgs are not closed, i think of
	them as open to the public and therefore exposed.
	it kind of helped when the press folks were given
	special name tags, but in a room w/ 50-100 people,
	it was tough to know who was holding on to the sheet
	and transcribing off it.  (not to pick on the press
	per se about email harvesting - they are more likely
	to fabricate a sensational report w/o getting the speakers
	permission - but the effect is similar.  these mtgs
	are public.)

-- 
--bill

---

From: Bill Manning <[email-masked]>
Date: Tue, 25 Mar 2008 11:57:17 -0700

> I thought the standard solution to Bill's problem was to write  

	not a doctor or a lawyer.... and i have enough ethics
	left to not forge Steve Coya's name anymore.

--bill

-- 
--bill

---

From: Marshall Eubanks <[email-masked]>
Date: Tue, 25 Mar 2008 15:12:37 -0400

> 	them as open to the public and therefore exposed.

True. After that, however, they are well guarded.

Regards
Marshall

---

From: "Steve Silverman" <[email-masked]>
Date: Tue, 25 Mar 2008 17:21:57 -0400

The Blue Sheets only tell you where someone was rather than where they
wanted to be.  I suggest having every registrant, indicate some number (5?)
of "Primary" WGs and a similar number of "secondary" WGs.  It should be
possible to derive a set of WG "conflicts-to-avoid" from that info.  This
would not be perfect but it would be a reasonable and automated starting
place.  Whether it would be better than the current system is TBD.  I think
there are just too many WGs and too few slots.  But nobody seems to want
shorter slots, longer meetings, or fewer WGs.  If somebody would invent
either a time machine or possibly a body doubler, it would make things
significantly more convenient!

Steve Silverman  

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Iljitsch van Beijnum
Sent: Tuesday, March 25, 2008 9:22 AM
To: Harald Tveit Alvestrand
Cc: IETF Discussion
Subject: Online blue sheets, was: Re: Scheduling unpleasantness

---

From: "David Harrington" <[email-masked]>
Date: Tue, 25 Mar 2008 17:39:18 -0400

Hi,

I think asking attendees during registration which sessions they
intend to attend and building a conflict matrix would be the simplest
approach. Of course, attendee conflicts matter less than ADs, chairs,
and presenter conflicts.

David Harrington
[email-masked]
[email-masked]
[email-masked]

---

From: Joel Jaeggli <[email-masked]>
Date: Tue, 25 Mar 2008 14:48:43 -0700

> approach. Of course, attendee conflicts matter less than ADs, chairs,

The best fit solution will be the one that screws everyone more or less 
equally...

---

From: Iljitsch van Beijnum <[email-masked]>
Date: Wed, 26 Mar 2008 13:38:28 +0100

> approach. Of course, attendee conflicts matter less than ADs, chairs,

Actually we pretty much have that today. You can get an auto-updating  
calendar from the tools page, with only the sessions in it that you  
select. So analysis of the sessions selected by people who use this  
tool could be illuminating.

A more formal mechanism like this would require more work both to  
build and to use, while the online blue sheet mechanism I have in mind  
will be extremely simple (no need to prepopulate it with sessions etc)  
and actually be somewhat more efficient to use than the existing blue  
sheets (which, I assume, will continue to exist).

On 25 mrt 2008, at 22:21, Steve Silverman wrote:

> place.  Whether it would be better than the current system is TBD.

I think these efforts could be complimentary.

> I think
> shorter slots, longer meetings, or fewer WGs.

The number of wgs isn't all that relevant except to the ADs, because  
nobody goes to uninteresting wgs. In a way, the meeting could be made  
slightly longer: on one occassion last year, the RRG met for the  
entire friday. This was very useful and would have reduced my overlap  
a good deal this time, but the chairs couldn't get all day friday this  
time, I assume because the rooms were no longer available friday  
afternoon. (I'm not advocating making friday afternoon part of the  
regular schedule, though.)

One thing that could help is split the morning sessions in two so more  
granular scheduling can take place. I'm also unsure why we need a 50  
minute break before the plenaries.
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---

From: Dan York <[email-masked]>
Date: Wed, 26 Mar 2008 10:19:00 -0400

On Mar 25, 2008, at 5:21 PM, Steve Silverman wrote:

> wanted to be.

I'd also note that people may wind up on multiple Blue Sheets.  I  
know that I have started in one WG and signed the Blue Sheet there  
and then wound up in another WG [1] where I have found myself signing  
a second set of Blue Sheets.

Regards,
Dan

[1] Either the first WG wound up early (it *has* happened!) or more  
often there has been a presentation in the second WG that I wanted to  
attend and so I've moved over there after the presentations in the  
first WG that I wanted to see were done.

-- 
Dan York, CISSP, Director of Emerging Communication Technology
Office of the CTO    Voxeo Corporation     [email-masked]
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