The key purpose of this type of analysis is to provide insight into the manufacturing technologies' overall contribution to
CoGs at the product level. Simply running these seven scenarios and comparing the outcome to the stainless steel facility
allows for a quick assessment of the financial benefit. In Table 1, the results show that for this case, the big cost wins
are the following: (in order of priority):
- use of hold bags for buffers (reducing CoGs by 8.3%)
- bioreactors: greater throughput is seen as a result of the faster turnaround of these systems compared to stainless steel
(reducing CoGs by 5.2%)
- mixer with open liners for buffer preparations (reducing CoGs by 4.8%)
- use of hold bags for product (reducing CoGs by 3.7%)
- disposable membrane absorber for the flow-through chromatography column (reducing CoGs by 3.2%).
Table 1. Disposable technology options (MAb, 3 x 2,000-L bioreactors at 2 g/L, 90% utilization)
More importantly, this analysis also highlights technologies that do not have a significant impact on cost, which in this
case is the use of sterile mixing systems for buffer and media preparation (items 2 and 4 in Table 1).
Finally, the overall impact of all the component contributions can be assessed. In this scenario, using all the disposable
technologies at once achieves an overall CoGs savings of 22.8% and an overall reduction of 36.8% in the capital. When adding
multiple disposable technologies together in a process, it is not necessarily true that the savings seen will match the sum
of the savings seen when each is added individually, because the savings can overlap. It is important therefore to assess
the combined effect to evaluate the overall impact.
Analyzing in detail how and where the cost savings arise allows us to use this information during supplier negotiations. For
example, though disposable bioreactors save significant capital (a reduction of 12%) this only equates to a CoGs saving of
5.2% because of the high cost of the disposable bioreactor components. Therefore, you should focus discussions with the supplier
on reducing the cost of consumables.
The analysis of the individual technology contributions is only the start of the assessment. We can now explore how these
savings are affected by changes in plant utilization, scale of operation, and processing technology.
One of the significant benefits of disposable technology is that it allows risk mitigation. The stainless steel facility has
a higher proportion of upfront fixed costs whereas the increased consumable costs for disposable technologies are activity
based and are only incurred when the facility is operational. Figure 2 illustrates the impact of facility utilization on the
savings of the disposable option compared to a base case of using stainless steel. At low utilization rates, the relative
savings of the disposables option is high, with peak savings of 31% at a utilization rate of 10%. With either stainless steel
or disposables, the cost of goods is higher at low utilization rates, but in the case of the disposables facility, the difference
is not as great in cost between low and high utilization rates, which means that upfront risk is lower.