D5 Annex report WP 3: ETIS Database methodology ... - ETIS plus

More documents

Recommendations

Info

D5 Annex WP 3: DATABASE METHODOLOGY AND DATABASE USER MANUAL – FREIGHT TRANSPORT DEMAND Table D.2 Example of Container Registration Mode Container Meaning Sea Road Yes No Commodity transported over sea in a container Commodity transported by road not in a container A possible extension to this method is to include also a type of container (large, other) on the place where otherwise a ‘yes’ would occur. Still a further extension would be to include in stead of a variable for container only, a variable for classification of loading units types. Should there be a Restriction on the Number of Links in a Transport Chain? Combining all the solutions in the previous paragraphs for the problems encountered in the computer example we see that for registering one flow, many variables are needed. If we take a look at the transportation of the computer from point A to point F we see that six locations have to be registered. One origin, four transhipment locations and a destination. Also five modes (one for each link) have to be registered together with the passive modes and container indications. This means 21 (= 3 x 5+ 6) variables are necessary for this transport chain. Furthermore variables are needed to describe the commodity, the weight and the value. Many transport flows will be less complex but there will also be more complex transport flows meaning that even more variables are needed. A partial solution to reduce the size of the database is to use a dynamic data structure in which for every transhipment place a variable is ‘made’ in the software. This means that sophisticated software has to be developed. The flow structure however still will be complex and difficult to comprehend. Another more pragmatic solution is to restrict the number of links. This also has disadvantages however, since it is important in case of intermodal transport to describe all transhipment that takes place. Furthermore reducing the number of transhipment points in the database also has some negative impacts on the reliability of the information to be extracted. To get more insight in this a look will be taken at the example in figure 5.4 158 Document2 27 May 2004
D5 Annex WP 3: DATABASE METHODOLOGY AND DATABASE USER MANUAL – FREIGHT TRANSPORT DEMAND Figure D.4: Flow with two Transhipments A B C D road sea road In this figure a transport flow can be seen from point A to point D with transhipment in point B and point C. In point B the commodities are transhipped from a truck to a ship and in point C from this ship to another truck. In case a record structure is considered where at least two transhipment points are possible, all information can be preserved. In case a restriction on the record structure is made, which makes it possible to include only one transhipment point part of the flow information has to be left out; not only one transhipment point has to be left out but also one mode. In the following table all possible registrations in this case are listed. Table D.3 Possible Registrations of the Example in Figure D.4 with one transhipment variable Record Origin mode 1 transhipment mode 2 Destination 1 2 3 4 A A A A Road Road Road Sea B B C C sea road road road D D D D The four possibilities are the result of two choices: 1. which transhipment point to chose? 2. which mode to chose? Without additional information on the transhipment points no good answer can be given on question 1. It can be recommended however to make one decision rule for the whole database. For example priority can be given to certain transhipment points. This means that in case this transhipment point is in the chain it will be chosen with higher priority than others. As a result, when analysing the total transhipment in for instance a port, the figures of the port with the highest priority will be the most complete. This also means that data for the other ports are not complete. Using other decision rules implicates that none of the transhipment points will have complete data. Several options can be chosen for the modes to be included. Document2 27 May 2004 159
Page 1:
D5 Annex report WP 3: ETIS Databa
Page 4 and 5:
D5 Annex WP 3: DATABASE METHODOLOGY
Page 7:
Page 10 and 11:
Page 12 and 13:
Page 14 and 15:
Page 16 and 17:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67:
Page 71 and 72:
Page 73 and 74:
Page 75:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108: D5 Annex WP 3: DATABASE METHODOLOGY
Page 133: ANNEX C: EXPERIENCE FROM CONCERTED
Page 157: D5 Annex WP 3: DATABASE METHODOLOGY
show all

D5 Annex report WP 3: ETIS Database methodology ... - ETIS plus

Create successful ePaper yourself

Delete template?

Save as template?