Complexity groups 2, 3 4 & 5

An analogue analysis has been performed with the remaining complexity groups. The tables and graphs illustrating the results can be seen in Appendix 11 to Appendix 20. A summary of the results is provided below.

For items of CG2, as expected, there is in general an increase in UTM in comparison to the items of CG1 as a consequence of the higher manufacturing complexity (Appendixes 11 and 12), thus ICC also tends to be higher. The warehousing related cost CWH is not significant, a pattern that is expected to recur as this is a fixed cost of $0.70 and the three other cost components are variable and tend to be higher for the remaining complexity groups. It can be seen that as the manufacturing complexity of the items increase, the 3DP and finishing labour become more intensive

(Appendixes 13 and 14). When the entire CG2 range is analysed, there are 4 items to which the total costs to 3D print are lower than the sum of the TM costs, and these are: SN1-08, SN8-12, TEF-PTCS12 and TEF-PTCS24. For SKU SN1-08, the cost ICC is significantly large in comparison to the ICC component of the other SKUs of the same sub-group. Investigating further, it can be seen that this is a consequence of the low stock turn of the item: 0.025. In other words, if the sales rate does not change, the amount in stock of this SKU will be carried for approximately 39 years. While the inventory carrying cost is an important aspect of stock to be considered in this analysis, this is a clear case of excessive stock overage, given that the annual demand is significantly higher than the MOQ. Therefore, even though the initial results pointed out to the direction of 3DP this particular SKU, this is not the case. The same analogy is true for SN8-12 and TEF-PTCS12. The result is however different for SKU TEF-PTCS24, and it indicates that this particular item should in fact be 3D printed. A comparison of its cost components can be seen on Figure 5.4:

While the SKU above yields a positive answer in regard to the use of the 3DP technology, the inequation’s result indicates that the benefit is relatively low and equates to $0.74.

Regarding CG3, while not a compulsory trend, it can be seen that in general the unit cost UTM of the items has increased when compared to those of CG1 and CG2 (Appendix 15). Once again it can be seen that TRAW is not a significant cost and can be considered negligible when compared to other 3DP costs such as CFIN or C3DP (Appendix 16). In particular for the items of CG3, TRAW corresponds on average to 0.45% of the total 3DP costs. While the finishing cost CFIN remained the same in comparison to CG2, C3DP increased. Selecting the sub-group EEE to be analysed in detail as per Figure 5.5:

Figure 5.5. Sub-Group EEE: Traditional Manufacturing Costs (CG3)

Figure 5.6. Sub-Group EEE: 3D Printing Costs (CG3)

The cost component UTM accounts for a large portion of the total manufacturing cost in comparison to the items of CG1 and CG2. For SKUs EEE020202, EEE040404, EEE080808, and EEE161616 of the sub-group analysed, the 3DP costs exceed the TM costs in $33.88, $38.20, $42.69 and $104.25, respectively, hence none of these four items should be 3D printed, on the contrary the 3DP costs in excess are considerably high.

Analysing the entire range of SKUs within CG3, there are five items that at first sight qualify to be 3D printed: AAA060606, AAA080808, AAA121212, AAA161616 and AAC080808. However, similarly to the SKU SN1-08 of CG2, this result is a consequence of the low stock turn (i.e. stock not being managed efficiently) rather than the benefits of 3DP exceeding the costs of TM.

CG4 comprises SKUs that are composed of at least 2 assemblies. This means that while these parts can be 3D printed as a single item, via manufacturing means there is the need of extra labour to attach the parts, work that may be performed by a worker or a machine. From a 3DP

perspective however, items grouped under CG4 require longer 3DP and finishing times (Appendixes 17 and 18), therefore increasing the total 3DP cost of the SKU. The sub-group K025 has been chosen to be analysed in detail and is shown on Figure 5.7:

Figure 5.7. Sub-Group K025: Traditional Manufacturing Costs (CG4)

Figure 5.7 shows that for the SKUs of sub-group K025, UTM is the largest cost component. followed by the cost of obsolescence COB. Similar to Figure 5.7, Figure 5.8 shows the 3DP costs:

Figure 5.8. Sub-Group K025: 3D Printing Costs (CG4)

It is noticeable that as a result of the higher item’s weight, the cost component CRAW overtakes or approximates CFIN. SKU’s K025-0808 and K025-1008 have been selected and a comparison between TM and 3DP costs is made on Figure 5.9:

Figure 5.9. Sub Group K025: Traditional Manufacturing vs. 3D Printing Costs

Even though the items grouped under CG4 are deemed to have a higher manufacturing complexity, the same trend that is observed in CG1, CG2 and CG3 repeats for CG4: the sum of the costs associated with 3DP exceed considerably the TM costs. In particular, due to the relatively long 3DP times of CG4, the cost component C3DP by its own would in general suffice. Analysing the results on both sides of Inequation (3), it can be seen that no items would qualify to be 3D printed.

Items comprised within CG5 have a UTM on average approximately three times higher than those items of CG2 and CG3 for instance (Appendix 19). In comparison to the other complexity groups, CG5 has the highest CFIN and C3DP, $11.81 and $49.51 respectively (Appendix 20). While the complexity of an item tends to favour the use of 3DP according to the literature review, it is still not the case for the items of CG5 in question. The sub-group PVV3 has been chosen to be analysed in detail:

Figure 5.10. Sub-Group PVV3: Traditional Manufacturing Costs (CG5)

Figure 5.10 shows that for the first time, the unit cost UTM is higher than the sum of the three other cost components ICC, CWH and COB, fact that partly reflects the high manufacturing complexity of the item. For the items of CG5, the cost component CWH accounts for 2.4% of the total, therefore not as significant as for the items of the other complexity groups. The corresponding 3DP costs are as follows:

Figure 5.11. Sub-Group PVV3: 3D Printing Costs (CG5)

From Figure 5.11 it can be extracted that CRAW and C3DP are the two largest cost components, followed by CFIN. It can be seen that the costs of 3DP the items of CG5 exceed the TM costs by a substantial amount. When the whole CG5 range is analysed, once again no items would qualify to be 3D printed.

As could be seen above, the analysis of the scenario µ=80%, IR = 10% and β = 1% yielded negative results regarding the use of 3DP to manufacture the items of the stock of the business analysed in this research.