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# Clear the mess on BDOM - Part II

Raj Polikepati
Greenhorn
Posts: 9
Hi,
Sorry for using a scenario. Because there has been some much discussion on this group and there is lot of prose confusion going on. We (Software guys) are more of mathematicians than literature guys.I thought a new way to discuss this thing. I would greatly appreciate the approach taken by certified SCEA because they sailed the boat successfully.

Scenario:
MCI (kansas city) to SFO (San Fransisco) and back

While going Segment:
MCI -> Denver (Price 100)
Denver -> SFO (Price 200)
Total one way price (300)
or
MCI -> Utah (Price 150)
Utah -> SFO (Price 230)
Total one way price (380)

While returning segment:
SFO -> Denver (Price 100)
Denver -> MCI (Price 260)
Total one way price (360)
or
SFO -> Utah (Price 150)
Utah -> MCI (Price 260)
Total one way price (410)

Total price of itinerary which is combination of 4 segments is:
300+360
or
300+410
or
380+360
or
380+410

Right?
Then where does the thing called Flight come into picture? Please !!!
Also I understand that assignment does not need this kind of analysis, if we were to follow the Design by Contract approach, just declaring the contract. But I feel it is better to describe it in attached documentation.
Thanks for your time and i would appreciate this scenario based approach for further discussion to avoid the ocean of prose.
Thanks
Raj

James Wang
Ranch Hand
Posts: 102
Raj,

I think the system need be analyzed as what you said. In business domain model diagram of the assignment document,the relation between itinerary and segment is one to many. That is one itinerary can contain one or more than one segments,if one itinerary contains more than one segments,it is fit for the scenario you mentioned.

Let me give an example:

If there is a direct flight from city A to city B,then the itinerary from A to B contain only one segment.

If there is no direct flight from city A to city B,then customer has to travel from A to C first, then from C to B finally. In this scenario, the itinerary will contain two segments, one is between A and C, another is between C and B.

In conclusion, If one itinerary contains more than one segments, it hint that there is no direct flight from departure city to destination city. that is the customer will have to transfer flight in somecity for finishing the travel.

Parag Doshi
Ranch Hand
Posts: 317

SFO -> Utah (Price 150)
Utah -> MCI (Price 260)

Just a simple question : Where did u define the relationship btw the
sfo->utah and utah -> MCI segment? In other words, how would you figure out the 1st segment is SFO-Utah and the 2nd is Utah->MCI?

Parag

Raj Polikepati
Greenhorn
Posts: 9
Parag,
You can map it in a mapping table possibly. I still believe the assignment doesnt require us to provide that information, because it is implementation specific.
Thanks
Raj

Sangmin Lee
Greenhorn
Posts: 7
Customer must select segment.

Segment is not selected by automatic logic.

I think that if customer selects FROM area and To area,

good system shows best ways and all ways(available segments)

, but general system shows that "No direct way, select segment" message.

Selecting segment is customer's choice.

James Wang
Ranch Hand
Posts: 102
Sangmin,

Customer must select segment.

Segment is not selected by automatic logic.

I think that if customer selects FROM area and To area,

good system shows best ways and all ways(available segments)

, but general system shows that "No direct way, select segment" message.

Selecting segment is customer's choice.

If so I think the assignment need not cover this scenario.

Parag Doshi
Ranch Hand
Posts: 317
Originally posted by Sangmin Lee:
Customer must select segment.

Segment is not selected by automatic logic.

I think that if customer selects FROM area and To area,

good system shows best ways and all ways(available segments)

, but general system shows that "No direct way, select segment" message.

Selecting segment is customer's choice.

Sangmin,
If there are no direct way, you would still need some logic to figure out what are the segments which can be shown. For example. to go from Point A to point C, if there are no direct flights, you would have to show:

Point A to Point B (and then all segments from Point B to C)
Point A to Point D (and then all segments from point D to C)

none of the airline reservation systems online do it that way..they generally say:

option 1 # Point A to Point C connecting at B
option 1 # Point A to Point C connecting at D

that way the connecting segments are always choosen as per some route/flight schedule and shown to the user. I was not suggesting that we need to know what algorithm is used to group these segments, all I was suggesting was that the segments are already grouped when they are shown to the user and hence it might make sense to show that relationship in our class diagram. You can see http://www.expedia.com as an example.

Parag