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Author Topic: Long term playability vs. slots  (Read 2987 times)

Offline LemonButt

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Re: Long term playability vs. slots
« Reply #40 on: July 20, 2013, 02:37:36 PM »
dmoose--I think sami is only implementing this on the destination airport and not the base, so you'd be forced to takeoff at the same time, but the turnaround times at the destination would be changed.

After typing that, I realized that wouldn't work though.  If you had a 737 with a 90 minute turnaround (for example) and wanted to put a widebody with a 3 hour turnaround on the route, you would have to change the time slots at the base airport as well :(

sami--even if you kept the total slots at the airport fixed, I think you'll end up with a lot of extra slots during rush hour as players find a way to game the system by moving 3am slots to 6am, etc.

Offline ezzeqiel

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Re: Long term playability vs. slots
« Reply #41 on: July 20, 2013, 04:22:14 PM »
After typing that, I realized that wouldn't work though.  If you had a 737 with a 90 minute turnaround (for example) and wanted to put a widebody with a 3 hour turnaround on the route, you would have to change the time slots at the base airport as well :(

You'll also have to move your base slots when transitioning from props to jets... departure hours are different... I have several props scheduled to arrive just at 0500 or 0600 am (overnight flights)... with jets that'd move several hours early and won't work...

Offline EsquireFlyer

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Re: Long term playability vs. slots
« Reply #42 on: July 20, 2013, 05:48:13 PM »
I have been specifically buying remote slots that work for both jets and props, so that I can fly them now on props and still be able to use them on jets later...which really narrows the time slots I can use at the prop stage because i have to make it jet-compatible.

It's a lot of work..so if you decide to implement this feature, please make a big announcement so I can stop doing my double-planning.  :)

I agree with others that it's amenable to abuse. And yet the prop to jet thing is quite hard with slot-locked remote stations (which is why I am doing all this pre-planning, although it will go to waste if the new system is implemented).

Maybe make it take longer than 5 years, but instead like 10 years? Or is that too long?

Also, what does it mean that the whole airport cannot increase slots if a single hour is >100%? It seems that that will easily break the slot increase system and actually cause more congestion (unless I am reading it wrong).

Offline LemonButt

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Re: Long term playability vs. slots
« Reply #43 on: July 20, 2013, 06:43:48 PM »
Also, what does it mean that the whole airport cannot increase slots if a single hour is >100%? It seems that that will easily break the slot increase system and actually cause more congestion (unless I am reading it wrong).

If an airport has 10 slots/hour and you have an aircraft scheduled for 5am and the slots look like this:

5am: 10 slots used, 0 avail
6am: 10 slots used, 0 avail

It will go to this if you move to 6am:

5am: 9 slots used, 0 avail
6am: 11 slots used, -1 avail

The total slots remain fixed, but the hourly slots are "fluid".  After slot growth:

5am: 9 slots used, 1 avail
6am: 11 slots used, 0 avail

So in essence, sami is fronting the slot growth for certain hours to make this work as the slot usage will be at the detriment of future growth if I understand this correctly...

Offline LemonButt

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Re: Long term playability vs. slots
« Reply #44 on: August 03, 2013, 02:52:15 PM »
I just had an idea on this that I can't believe we haven't thought of yet.  It mixes the two methods of having an artificial cap as well as a market-based system for slots.

Let's say an airport has 50 slots/hour that are all used up.  Let's give each airport a fixed growth metric, such as 10% growth per year.  So an airport grows from 50 slots to 55 slots to 61 slots to 67 slots over a 4 year period.  This is the artificial cap part of the program.

The market-based part is a "slot presale" system.  Airlines can buy the new slots using an auction-style system and have them reserved for them based on the amount of money they want to contribute to fund expansion.  So if an airport is growing by 10 slots/hour (for simplicity), lets say that only 60% of slots are available for "pre-sale", or 6 slots per hour.  The year before the slot growth happens, airlines can bid on those slots using an auction-based system.  So 6 slots/hour available means there will be 6 winning bids.  This would be one of the largest auctions as you can expect there to be only 1-2, maybe 3 slots available to reserve as most airports don't expand by more than 5 slots/year.  In order to give the smaller airlines a fighting chance, you would bid with a % of that year's revenue.  So if you did $100 million in 2013 and bid 1%, that is $1 million.  If a large airline did $1 billion, they would have to put up 1% or $10 million in order to match the bid.  Then in 2014 they'd have the slots reserved for them for a period of 1 year in a use it or lose it scenario.

Here is a step-by-step:

1. The year is 2013 and an aiirport plans on 10% growth, adding 10 slots/hour in 2014.
2. 60% of the slots are available for "pre-sale" in an auction format (1 slot/hour packages, which is 24 slots/day spread out across every hour for airports without curfew)
3. Airlines bid a % of their 2013 revenue on the slots.
4. The highest bidders pay their winning bids to the airport to secure the slots on Jan 1, 2014.
5. The airlines have slots reserved for a year.  The reservation expires Dec 31, 2014 and then go into the general slot pool.
6. When an airline uses reserved slots, they are already paid for and cost $0 to buy.

Since smaller airlines have less overhead as a percent of revenue, this should give the small airlines an edge over the larger ones since you bid % of revenue.  This also makes it easier for larger airlines to fail as it will take substantial sums to compete with the smaller airlines in the auction.  Large airlines also predominantly fly the long haul routes which are hit hardest when fuel prices spike, so if they burn all their cash in the auction and are over-leveraged with loans it will be the death knell.  Also, since the slots expire after one year, airlines will need to have aircraft orders in or otherwise have extra cash available for aircraft to actually use the slots.  This adds a whole new element to the game IMO and would be a good middle ground between "first come first serve" and a "the airline with the most money wins" setup.

exchlbg

  • Former member
Re: Long term playability vs. slots
« Reply #45 on: August 03, 2013, 05:19:56 PM »
I doubt Sami will implement any kind of auction.Besides, that was proposed many times before.

AndyS10

  • Former member
Re: Long term playability vs. slots
« Reply #46 on: August 08, 2013, 10:29:21 PM »
Hi,

I am new to AWS, and still getting the hang of the intricacies of the game, but I do have extensive RL experience with airline scheduling and slots which I think may be of relevance to this discussion and Sami’s initial suggestion.

My background is in Europe and whilst there may be some differences in North America, I don’t think there is much variation given that the rules and regs for allocating slots are managed by IATA. These rules are set out in the Worldwide Slot guidelines (WSG) http://www.iata.org/policy/slots/Documents/wsg-5.pdf
although airports and the locally based airlines can agree certain minor variations (Local rules) which apply to that airport only, these do not contradict the fundamental principles of slot allocation.

Ignoring uncongested airports, where airlines can come and go as they please, for major airports which suffer congestion at peak times (classed as Level 3 or SCR airports in IATA terminology), slots are allocated according to WSG rules. Airlines can apply to change their schedules or apply for new slots at any time during the year, however, they have more success in achieving their aims if they organise their major schedule changes around the biannual slot conferences. In effect all the airlines operating to an airport revise their planned schedules for the coming season at the same time and the airport coordinator matches demand to capacity as best they can. The order of priority that the Coordinators apply in determining which airline gets what is as follows:

1.   Historic slots – that is if you have operated a flight at a given time last year, you are entitled to the same timed slots again this year.
2.   Historic Retimes – if an airline with historic slots wishes to reschedule a flight, the coordinator attempts to move the old slot onto the newly requested time (or close to it) before addressing other demands
3.   The slots that are left (any unclaimed Historic slots and any new capacity that the airport or ATC have agreed can be released) are allocated out, with 50% being reserved for “New Entrant” airlines. The definition of “New Entrant” has varied over the years, but is currently defined as an airline which holds less than 5 slots on the day for which they are applying for the new slot – note that an arrival counts as a slot as does a departure so this means a carrier with less than two daily rotations from an airport can request New Entrant status. In reality this means that New Entrant status only applies to non-based airlines. The remaining 50% of slots are available to all other carrier requests.

Over and above the formal rules for allocating capacity, airlines can and do trade slots between themselves. Note that IRL, the value of slots defers to the airline, not the airport, much to the airports’ displeasure. I can apply and obtain a slot at an unconstrained airport and I pay nothing. Or I can sell my slots at a constrained airport to another airline and pocket the cash. If I want to fly out of JFK at peak time, it is not the airport I need to pay, but an existing operator with a slot/gate and stand at the times I want. Or I can apply to the JFK coordinator year after year for a slot and get told that nothing is available in the hours that I have requested.

IRL there are airline business models which involve operating cheap turboprops into congested airports in order to build up a slot portfolio which has an inherent value and can then be sold on in part or in pieces. Note that the more historic slots an airline has, the better its ability to access peak time slots as over time, through repeated (bi-annual) historic retime requests, the airline will eventually get its 04:00 departure moved to 06:00 or even 07:00 or 08:00 as other carriers go bust, lose their rights to historic slots or request moves out of the congested hours.

In terms of adding a “market based” approach to slots, slot trading between airlines is it. The price a carrier wishing to operate a long haul wide-body is prepared to pay for a slot sets the opportunity cost for an existing carrier operating small aircraft on regional services.  This is why you rarely see an ATR 42 at LHR…..

Another point which may be too complex for AWS now, but for which the basic infrastructure already exists is the performance and use it or lose it rules – airlines which routinely operate late can lose their rights to historic slots, a major blow at a congested airport. Likewise if an airline operates less than 80% of the slots it holds, it will also lose its historic rights to the slots. This is a basic method of avoiding slot hoarding. A simple rule on repeated poor punctuality leading to loss of slots would add realism to the game and force players to give due weight to their turn-round times and scheduling as well as occasionally freeing up slots at congested airports in peak hours.

Based on the real life rules, I would suggest that a system which reserves 50% of any new capacity being released for the non- based carriers at a given airport would go some way to solving the problem of early players being able to dominate a given airport, as long as capacity is slowly and steadily increased over time. IRL capacity is slowly increased, even at airports which aren’t having new terminals or runways built. Often capacity improvements come in the form or one or two movements per hour as ATC review the delay statistics, the airport adds some rapid exit taxiways or reorganise the layout of the terminal to allow more international (or domestic) passenger throughput. Note that this new capacity is first available to retime an existing carriers slots. So if an  airport adds one movement in every hour, the request of an existing airline to move a slot from 09:00 to 10:00 would be met first and then the new entrants could pick up a slot in 09:00 or 11:00 or hour other than 10:00.

I’m not sure how you would devise a system which allows an airline to move its slots between capacity constrained hours over time without requiring immense processing behind the scenes in order to avoid busting the set hourly capacity limits. In essence, what you need is a wait list, with carriers bidding to move their existing slots into a new time as and when capacity becomes available, either through expansion or other carriers going bust or moving their slots out of the hours in question. The system Sami proposed of allowing airlines to bust the limits on certain hours whilst maintaining the overall cap on movements seems likely lead to certain hours being heavily (and unrealistically) oversubscribed over time.

Offline JumboShrimp

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Re: Long term playability vs. slots
« Reply #47 on: October 03, 2013, 04:23:34 AM »
Airports that end up having no slots seem to be located mainly in Europe or Asia. If the objective is to provide better access to everyone to the (relatively few) slot restricted airports, then perhaps a much easier solution could be to just increase the total amount of slots in those (few) airports such as (LHR, FRA, NRT etc?). That might address the issues maybe in a more efficient way rather than creating another artificial limit?

The easiest solution is to make the slot growth completely dynamic, with no presets, other than what the airport starts with at the beginning of the game world.

Another slot hogging prevention method which I posted to another thread earlier is a slot quota. In other words each airline is limited to X % of the available slots each game month. Easy method to prevent the f5 spam...

Slot hogging and slot locking an airport is only there because players know there is a limit, and the limit can be exploited by buying up the slots, creating a monopoly.  The limit itself invites slot hogging and attempt to slot lock the airport.

Remove the limit, and the players will know that there will always be slots added (airport expanded), and the desire to hog the slots will not be there any more, and everyone will know that they can't slot lock the airport, period, so no need to even try....

Some airports in RL grow very quickly, when the demand is there.  One such airport I have been flying to, VIE, probably grew by factor of 3 in last ~30 years.  So there is a precedent...

Another 2 issues is playability and competition.

RL issues vs. playability should be considered, playability should be a factor.  If small bending of RL restrictions will greatly increase playability - than why not?

Airports formerly slot locked by the incumbent airline may be subject to more competition, if the competitor knows that the slots will be there for him if he decides to compete by opening a base at a monopoly airport.

Knowing for fact that there will be slots at airports such as LHR, CDG, FRA may also slow down the rush to fly to them.  A lot of players rush to these airports, not only because of potential profit, but also out of fear that if they don't grab the slots early on, it may be nearly impossible later on.  Knowing there will definitely be slots may slow down this rush by outside airlines as well...

As far as expansion, maybe when an airport is below certain % of slots in 0500-2300 hours, system can add a non-trivial "airport expansion fee" on all existing slot holders - per slot.  The airline most heavily affected by the fees will be the slot monopoly holder...  So in effect, the person slot locking the airport would be funding the unlocking of the airport...
« Last Edit: October 03, 2013, 08:48:27 AM by JumboShrimp »

BD

  • Former member
Re: Long term playability vs. slots
« Reply #48 on: October 03, 2013, 03:15:50 PM »
As far as expansion, maybe when an airport is below certain % of slots in 0500-2300 hours, system can add a non-trivial "airport expansion fee" on all existing slot holders - per slot.  The airline most heavily affected by the fees will be the slot monopoly holder...  So in effect, the person slot locking the airport would be funding the unlocking of the airport...
Interesting idea.

Seems that it could most easily be implemented as part of the landing fee. 

Could the effect of this be to discourage new entrants to an existing airport?  I don't know the answer to that, but it is a question I have.




 

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