What is claimed is:1. An information processing system comprising:a processor configured to add print jobs to be allocated to one roll of rolled paper, one print job at a time, in a range in which a remaining amount of the rolled paper is not exceeded; dynamically change an estimation of a time needed to execute each print job previously added for the one roll of rolled paper to reflect print parameters changed because of the added print jobs; and in a case where there are a plurality of candidates for an added print job, each including a transport speed that is higher than a transport speed determined for the combination of print jobs that have been allocated, determine to add one of the plurality of candidates with a transport speed that is the lowest of the plurality of candidates.2. The information processing system according to claim 1, wherein the processor is configured to:in a case where there are a plurality of candidates for an added print job, each including a transport speed that is lower than a transport speed determined for the combination of print jobs that have been allocated, determine to add, one of the plurality of candidates with a transport speed that is the highest of the plurality of candidates.3. The information processing system according to claim 1, wherein the processor is configured to: select a print job that uses a longest length of paper, among unallocated print jobs, as a first print job to be allocated to the rolled paper.4. The information processing system according to claim 2, wherein the processor is configured to:select a print job that uses a longest length of paper, among unallocated print jobs, as a first print job to be allocated to the rolled paper.5. The information processing system according to claim 1, wherein the processor is configured to:add print jobs to be allocated to the rolled paper, one print job at a time, in a descending order of speed needed to process the print jobs in the range in which the remaining amount of the rolled paper is not exceeded.6. The information processing system according to claim 1, wherein the processor is configured to:dynamically change the estimation of the time needed to execute each print job at a time when the print jobs allocated to the rolled paper is determined.7. A non-transitory computer readable medium storing a program causing a computer to execute a process comprising: adding print jobs to be allocated to one roll of rolled paper, one print job at a time, in a range in which a remaining amount of the rolled paper is not exceeded; dynamically changing an estimation of a time needed to execute each print job previously added for the one roll of rolled paper to reflect print parameters changed because of the added print jobs; and in a case where there are a plurality of candidates for an added print job, each including a transport speed that is higher than a transport speed determined for the combination of print jobs that have been allocated, adding one of the plurality of candidates with a transport speed that is the lowest of the plurality of candidates.8. An image forming system comprising: an image forming apparatus that forms an image on rolled paper; and an information processing system comprising means for adding print jobs to be allocated to one roll of rolled paper, one print job at a time, in a range in which a remaining amount of the rolled paper is not exceeded; means for dynamically changing an estimation of a time needed to execute each print job previously added for the one roll of rolled paper to reflect print parameters changed because of the added print jobs; and means for adding, in a case where there are a plurality of candidates for an added print job, each including a transport speed that is higher than a transport speed determined for the combination of print jobs that have been allocated, one of the plurality of candidates with a transport speed that is the lowest of the plurality of candidates.
