SECTION 4 -MORE ADVANCED FEATURES.
In the previous section you were introduced to the use of many of the basic features of CARGOMANAGER. In this section some of the more advanced features of the software will be introduced, using where appropriate the container packing example introduced earlier.
The features covered include:
A description of different approaches to the addition of cargo items.
An explanation of how multiple container shipments can be examined.
The effect of the container weight limit.
Speeding up calculation phases.
The levelling of cargo.
The development of a cargo Item database.
|4.7||Changing Container Size.|
|4.8||Weight Wizard - loading the maximum weight.|
4.1. Packing Additional Cases.
At various stages in CARGOMANAGER additional cargo can be specified for packing into the container. This may be done BEFORE any attempt is made at packing the container (i.e. before the end of the INPUT procedures), or, the additional cargo may be added to a container AFTER some cargo has been packed into the container by CARGOMANAGER.
These two situations differ in that in the former instance the additional items are added to the complete cargo list which CARGOMANAGER will attempt to pack, whereas in the latter the additional cargo specified will be packed (where possible) into spaces available around the cargo which has already been packed.
These two situations will be examined separately.
Once again this will be done in the form of a 'hands-on' exercise, though you may prefer to follow through the discussion without using your computer.
a. Adding Cargo Prior to Packing.
Start-Up CARGOMANAGER and select the DataFile option.
A number of .dat files will be shown as available - select the file manual.dat.
This is a file installed with CARGOMANAGER that contains the full details of the consignment entered manually by you in following the example of Section 3.
Select Proceed and then OK to confirm your choice and to move onto the Cargo Specification Screen.
For the present we will leave the data unchanged.
Select Cargo List Complete to move onto the Cargo Summary Screen.
As we noted during our examination of the problem in the previous section, the cargo as specified has a volume of 23.632 cu.m., compared with a container internal volume of 30.03 cu.m.. This represents a cargo that is 78.68% of the internal container volume. As we know from the previous section, this cargo can be fitted within the stated container.
We might therefore wish to continue with the packing of the container, or we might want to add additional items to the container load prior to packing.
Had the volume of the cargo exceeded the capacity of the container then we might have wished to pack what we could into the stated container, or to increase the size of the container used, or to change the quantities of the cases to be packed. A further option would be to calculate the number of containers required for this cargo.
At this stage we may therefore wish to proceed with the packing of the load as stated (by selecting PackCalc to move forward), or we may wish to step back one screen (using the Back button) to modify the cargo or the container details.
Let us assume that we wish to modify the number of cases of Product 4 that we wish to pack from the current 82, to a value of 130, leaving the quantities of the other three products which we would like to pack unchanged. Select Back to move back one screen to display Screen 3 - Cargo Data Entry. Having done this select Next 3 times to display the information relating to Product 4 and adjust the quantity entry from the current value of 82 to a new value of 130.
It would be possible to make changes to any of the displayed values (on this screen or the container details by selecting Contbase or Contdims at the top of Screen 3. We will just make the one quantity change on this occasion.
Select Cargo List Complete to return to Screen 4 - Cargo Summary.
We now see that the data we have specified a cargo of 101.89% of the container volume. We will not be able to pack all of the cargo, especially as some of the case types have been specified as fragile or heavy. When items are excluded, CARGOMANAGER will determine which need to be excluded using (on this occasion) the criteria of maximum container volume utilisation.
We now proceed with the packing of the cargo as specified.
Select PackCalc and accept the default saved.dat datafile.
The Calculation Phase will commence.
Once again the multi-stage packing process is carried out. Once they are complete 185 items (of 191 available) have been packed. A volume utilisation of 91% has been achieved.
To examine details of unpacked items select Continue to proceed to Results Screen.
This screen presents in tabular form the number of items of each cargo type packed / unpacked. In this case a few of Product 2 have been left out.
A somewhat more comprehensive printer report can be obtained by selecting Print.
As stated earlier the items excluded from the packing are chosen by CARGOMANAGER so as to maximise the total volume packed. The criteria for exclusion are discussed in more detail in Section 6 of this manual. Using the procedure adopted above to add cargo PRIOR to packing no priority has been specified to individual cargo types.
In some cases it may be essential to specify certain cargo which MUST be packed, and add to this additional cargo which should be shipped if space permits. This can be achieved in two ways, either packing the 'essential' cargo first and specifying the remaining items as additional cargo afterwards, or by specifying priorities for each cargo item from the start. (See Section 6)
On the Case Input screen (Screen 3) you will remember that we gave a priority of 1 to each Case Type. For any line of data a priority between 1 (high) and 99 (low) may be given, though usually values of 1 (high) to perhaps 3 (low) will be sufficient. Whether or not unequal priorities have been assigned from the start, there will be situations where it is desirable to add cargo to that already packed.
b. Adding Additional Cargo After Packing.
Having examined one method of packing additional items, let us now return to the problem as originally specified (manual.dat) and examine how additional cases can be added AFTER the 'essential' cargo has been packed. This approach to packing is termed in this manual as "End Packing".
Select the Re-Start option.
Here, as before, the name of a data file can be specified by selecting the DataFile option from the main menu.
Once again choose the manual.dat data file and leave the data unchanged.
Proceed to the point where PackCalc can be selected and select to perform the packing (as carried out in Section 3).
Once Calculations are complete and the packing results summary is displayed select Continue to show the tabular results screen.
A complete packing of all cargo has now been achieved, and some space remains in the container that may be suitable for packing with additional cargo. Earlier in this section we added 48 additional cases of Product 4 to our cargo list but found that their inclusion (which provided a cargo greater than the capacity of the container) resulted in a number of products being excluded.
Having packed all the 'essential' cargo, we will now add 48 additional cases of Product 4, and pack these within the spaces left in the container.
Select the Add Option from the option list.
You now have the option to merge cargo data held in a CARGOMANAGER file into the remaining space, or, more usually to enter additional cargo from the keyboard. The File option essentially merges data from an existing file into the current load.
If you select Keyboard entry then you will be presented with completed Cargo Data Entry screens similar to that entered by you as data for the above packing problem. It differs in two ways from the earlier screen.
The quantity column, which originally contained the quantity values input by you for each product to be packed, now contains zeros for the quantity entries (unless any had been unpacked).
The priorities values are all as previously entered (all 1 in this instance).
The size and weight details cannot be edited, though you can change some of the other fields to relax the packing constraints originally applied.
Use the Next button 3 times to move to the screen displaying information on Product 4.
You could add additional items of another case type, but in this case we will simply attempt to add an additional 48 cases of Product 4 to the existing (packed) cargo.
Using the procedure employed on earlier INPUT screens edit the quantity entry for Product 4 from zero to 48. Now select Cargo List Complete to display the Cargo Summary screen.
This screen provides details of the cargo already packed (143 items of 23.631 cu.m.) and the remaining capacity in the container (6.40 cu.m.). The additional cargo just specified has a volume of 6.97 cu.m.
Details are also given of the percentages that the added cargo represents of the total spare volume and weight.
It is clear that not all the additional cargo can be packed. In fact, the 6.40 cu.m. of the container currently unpacked is in part made up of small spaces left between / on top of cases already packed and thus may be unsuitable for packing the additional cargo specified.
Select PackCalc to perform the packing, once again accepting the default saved.dat datafile name.
During this phase details of the items already packed and the spaces remaining in the container are retrieved.
The additional cargo is then packed into the available space and, as with the initial packing calculation process, details of the progress of calculations is provided on screen.
Once calculations are complete, the total number of Cases packed is displayed together with details of the weight/ volume of the additional items successfully packed. A total of 163 items have now been packed (20 additional items).
Select Continue to show the tabular details. This screen is similar to that provided earlier, except that details of previously packed items are shown as well as the additional items.
Your screen should be similar to that shown. The Orig column contains details of the number of cases of each type packed PRIOR to adding the additional items, Now refers to the total number now packed, Left gives details of those ADDITIONAL cases which remain unpacked.
Once again you may proceed by selecting Draw to view the packing used on screen / printer.
As you have seen, the second method of packing additional cargo has the advantage that items originally input (and packed) are left in place and the additional cargo is fitted into the spaces remaining in the arrangement.
Although, from a practical viewpoint this second method of adding additional items may well be preferable, it is important to realise that CARGOMANAGER, in common with the personnel loading a container, is best able to provide highly efficient packings when the whole of the cargo to be packed is known at the time packing begins.
4.2. Packing Multiple Containers.
CARGOMANAGER has been designed with the objective of packing the greatest volume of cargo into a single container, but IS well able to tackle problems where a cargo has been specified which may require several containers to cater for its volume / weight.
If, during INITIAL data entry (not 'End Packing'), a cargo is specified which has a volume greater than a single container then CARGOMANAGER offers two possible solution routes.
a. Stepwise Multiple Container Examination.
By selecting PackCalc at this stage the best possible packing of the single specified container is carried out and unpacked cargo is saved so that the items may be easily packed into a second and subsequent containers.
Having examined the packing achieved in this first container you can then pack the remaining items into further container(s) by selecting NextCont .
Using this as data (with, if required, a different container size), the packing process can again be repeated and, once again, all packing / display / drawing for this container should be completed.
This process can be repeated for any number of containers as long as the input data meets the following constraints (Constraints which apply for ALL data input within CARGOMANAGER):
Total Number of Case Types : Less than 15,000
Total Number of Cases : Less than 50,000
b. One Step Multiple Container Estimation.
CARGOMANAGER also offers a MultiCont multi-container calculation mode. This is selected from the menu bar in the same manner as PackCalc.
In this mode the total cargo is packed in a single step into as many containers as are required. Each container is identical to that specified on the main container input screen. A screen summary is provided giving the number of items fitted into each container and the percentage fill obtained but no detailed cargo arrangements are available for any of the completely filled containers. The summary screen is illustrated below.
Once the calculations are complete miniature images of all the containers used as displayed on screen (12 to a page). Any of the containers can then be selected for detailed examination and printing.
[Just the left hand part of one such screen is shown below]
In this release the solutions obtained using the Stepwise procedure described earlier May NOT provide the user with the same solution as when using the One Step approach. This is because the MultiCont one step approach now utilises extra steps designed to further reduce the number of containers required.
The process of packing as much as possible into the first container, then taking the remaining items and packing as much as possible into the 2nd container and so on may not lead to a multiple container solution which minimises the number of containers used. Using this approach items that 'pack efficiently' may be 'used up' in the early containers, with 'awkward' items being left for later containers. Whilst CARGOMANAGER MultiCont does begin by determining the solution which it would achieved using this multistep approach it then goes on, wherever possible, to improve on this by either reducing the total number of containers required, or producing a solution where the final container has more free space.
4.3. Packing Subjected to Weight Limits.
The methods employed with CARGOMANAGER have been developed with the objective of maximising volume utilisation within a container, whilst taking into account priorities. However, the container weight limit input by the user IS used to limit the weight of cargo in any container to that specified.
In such instances the excluded items will be saved in the same manner as for items excluded due to lack of volume and if required be available for packing into a subsequent container.
During the calculation phases, if a greater volume utilisation could have been achieved had the weight limit not been in operation then an appropriate message is output on both screen and printer reports. The cases actually loaded will meet the stated container load limit.
In this release we have also added a powerful new feature - WEIGHT WIZZARD - to allow users who have problems in which their objective is to maximise weight and not the volume packed in a container to obtain such solutions. This is discussed in Section 4.8.
As detailed in Section 4.5 below, the Level option can be selected so as to provide a more stable packing arrangement than otherwise be obtained. Two different forms of levelling are available and these are discussed in Section 4.5 below.
4.4. Speeding Up Calculations.
Normally, the calculation time on modern computer equipment will be a matter of a few seconds.
However, especially when a cargo is specified which is sufficient to fill significantly more than a single container, and consists of many item types, then the number of combinations (i.e. possible packings of the first / subsequent containers) may be considerable. As noted on the Calculations screen - the use of the Escape Early button can be applied to 'jump' forwards. Where users experience problems with the time required for these computation stages, they should refer to Section 6 of this manual where the operation of this option is described in detail.
4.5. Load Levelling.
In operation CARGOMANAGER attempts to make maximum use of the container volume and, in doing so, carries out packing from the rear of the container forwards leaving as much space as possible towards the door of the container. There may well be situations in which the cargo to be packed is insufficient to give a high volumetric fill of the container volume and thus an arrangement in which the cargo is 'spread' over the container floor is required. The Level option provides for this to be achieved.
When selected a re-packing of the cargo which has currently been fitted into the container is carried out in an effort to achieve a more level load.
During the re-packing phase a screen is displayed showing the progress of levelling. Packing at a series of container height limits is carried out and the height limit currently being applied and the percentage of cargo fitted is displayed.
If, as described in Section 6, the packing option to allow 'layered solutions when levelling' has been specified, then in most instances just the final solution height will be displayed. Layered solutions are ones in which each item type in a consignment tends to be placed in layers over the container floor rather than in vertical blocks building from the rear of the container. These layers may well prove to be more stable in transit and experimentation will show whether they are desirable in a particular environment.
Where, during layering calculations, a moving bar is displayed, this is used to indicate the number of attempts being made at each possible height. Once a levelled arrangement has been found this is then displayed. If no improvement is possible then the un-levelled arrangement is re-produced.
As on the main calculation screens the Escape Early button can be used to 'Jump Forward'. On this screen this will result in only one attempt being made at each pre-determined loading height. This can result in a poorer levelling (or no improvement at all) being obtained. As described in Section 7 of the manual the user may choose which of the views (levelled or un-levelled) is to be utilised on the drawing screens.
4.6. A Cargo Database.
The entry of cargo details (Cargo description, size etc) may, in situations where the same product types are frequently encountered, prove somewhat time consuming. In order to overcome such problems it is possible to build up you own database of product descriptions and characteristics which CARGOMANAGER can access and thereby enter appropriate information into the screens for you. Information on up 25,000 items can the quickly accessed in this way.
Three procedures may be used to develop this database. It is possible to use a spreadsheet containing item descriptions, dimensions and weights to create an Itembase database using the MAKEIB utility - this is described in Section 10. A second approach is to use the inbuilt database program described in Section 10 which allows entry of Cargo Descriptors and dimensions on an item by item basis. Alternatively, having manually entered details of one or more cargo items into the input screen of CARGOMANAGER the ItemBase option is available (on the Cargo Summary Screen). This option saves all Case Information associated with the current problem into the database, updating any existing records with the new data. This is shown below.
During data entry, after entry of each product description (i.e. Case code/description), CARGOMANAGER will normally search the database for a product match. If one is found then the details of product size, orientation and layer constraints will be automatically entered on the data screen and the cursor positioned ready for the user to enter the quantity to be packed. The automatic database check can be switched off if required as shown below.
This process continues until all cargo items have been entered.
If the product description is NOT identified then CARGOMANAGER will request details of size etc in the usual way.
As described in Section 10, the number of characters of the case code / description which are to form a unique identifier can be modified by the user from the default value otherwise utilised.
In addition to the matching of Case Code / Description described above it is also possible to display the full Itembase on screen (using the Itembase option at the top of screen - see below). The database (Code/Description) is shown as an additional window (here the user has used numeric codes - 155.3585). By Double-Clicking on any entry the (currently blank) details for Item_E will be replaced with those held in the database for 155.3585.
In situations where a number of entries are to be selected from the Itembase then the sequence would be to 'Add more items' (which would display a screen with a description but with zero dimensions for case Length / Width and Height); then double click on the Itembase entry required, then enter the quantity of that item that will be in the consignment.
If the Shift key (or more conveniently) the Caps Lock key is used when double clicking this will avoid the need to repeatedly use the Add more Items key.
4.7 Changing Container Size.
Whilst Section 11 and Section 12 of this manual describe in detail how to examine the efficiency with which multiple container sizes may be used for any consignment, if all that is required is to change the container size to another single value, then at any time one can select a new Contbase container from the menu on the Cargo data Entry screen. This is shown below.
4.8 Weight Wizard - Optimising Weight Utilisation.
As previously discussed CARGOMANAGER packing functions normally focus on the maximisation of load volume (or load value). Where the resulting packing would be over the container weight limit, cargo is excluded so that the loaded cargo falls within the load limits. Whilst this will usually provide a suitable solution, it will not necessarily mean that the weight of cargo packed is as close to the container weight limit as might have been achieved had cargo items been 'juggled' to meet weight rather than volume limits.
This release of CARGOMANAGER now includes a powerful optimising tool - Weight Wizard - which will carry out the 'juggling' so as to provide a weight of cargo which is as close to the container limit as possible. In doing so it will also take account of items which the user stipulates must be packed. The routine is available in PackCalc mode (single container packing) and, as described below, when appropriate, the user will be prompted as to whether a weight based calculation should be carried out.
The approach taken by Weight Wizard is based on setting priorities for each cargo item in the consignment so that a set of those items which comes closest to the container load weight limit are packed first.
The screen below shows the prompt which may be displayed to you in PackCalc mode at the point after the consignment data has been saved to disk. It will be displayed only when all the following conditions are met:
The cargo list must contain 30 of fewer items.
Each item must have its own entry (i.e. the quantity to pack of each product code must = 1 - or zero)
The consignment must have a total weight which exceeds the load limit of the container.
When these conditions are true CARGOMANAGER will prompt you as below:
If you choose NOT to perform a weight based packing then the solution will (as previously) be carried out to maximise the volume packed, subject to the weight limit.
If you accept the option to perform a weight based packing then CARGOMANAGER will calculate how best to achieve a load close to the container weight limit and then make changes to the priorities associated with each item so that the packing that is then carried out attempts to achieve this. It should be noted that when both weight and volume are a problem (cargo weight greater than the container weight limit and cargo volume close to or greater than container volume) then it may not be physically possible to provide a solution close to the weight limit.
How this is done.
Many users utilise the priority coding that can be associated with each item in a consignment to indicate cargo which must be packed (Priority 1), and cargo which should can be packed once Priority 1 items have been loaded (larger values - e.g. 2, 10, 50 etc). In developing the weight based loading algorithms we were well aware that even for weight based problems there might still be Priority 1 items which must be packed, to which should be added other items so as to make the weight as close as possible to the limit.
In practice the following rules are applied.
If the priorities for all items are = 1 (the default) then CARGOMANAGER assumes that it may select freely from all items in an attempt to fall just within the load limits.
If some items have a priority 1, and others have larger priority values, then CARGOMANAGER assumes that the Priority 1 items must be packed, and calculates which of the remaining items (all items with a larger value) are best used to make up a consignment close to the weight limit. It then allocates these a Packing Priority = 2, with those items that if added would exceed the load limit given a Packing Priority = 51. Thus all items will then have values = 1, 2 or 51.
These changes are carried out automatically but do NOT change the values held in your saved .DAT file or any linkfile which may have been used. Thus you can go back and carrying out another packing, selecting not to use Weight Wizzard, and utilise the priorities you originally assigned.
Points to note:
The limit of 30 products is a function of the time taken to perform the load optimisation. Selecting the best set from 30 may take just a few seconds, but selecting the best set from 31 would take twice as long etc! We have applied the limit of 30 to provide the best balance between solution time and practical needs.
If you have a consignment which as well as being too heavy for the container is also likely to be difficult to fit on a volume basis then you might wish to examine solutions both with and without the Weight Wizzard weight based packing being used and compare these for suitability.
Obviously, if you pre-assign many of the cargo items (but not all) a priority value of 1 then there will be little or no opportunity for CARGOMANAGER to get close to the weight limit as most / all of the cargo to be packed will be pre-assigned. If Weight Wizard finds that in a consignment having various initial priority values the 'must pack' priority 1 cargo already exceeeds the weight limit then it will not make changes to the priorities.
The weights of cargo items and the container weight limit are held as numbers with a decimal part (e.g. 26000.0). Calculations of the actual load at any point are done to high accuracy but it may be beneficial to add just a small amount to the container load limit (e.g. say 26000.1 instead of 26000.0 ) to allow for inaccuracies which always occur in any program when manipulating numbers. Computers are not as accurate as you might believe!