Requirements and Limitations of Transformability

This subsection provides an overview of important requirements and limitations of the transformability of factories that have been recognised.

Kraemer (2013, pp. 106–107) argues that the location and the site are elementary factory elements, as they involve essential basics for the transformability of a factory. The site determines the development and shaping of functional areas inside and outside buildings. Locations and sites should be chosen carefully. This has been considered by Heger (2006, p. 97), who assigns potential ‘growth areas’, ‘growth directions’ and ‘s&d infrastructures’ to the area-scalability. That the amount/

number of these areas and directions must be considered, is shown in Hernández (2002, p. 89).

According to Helbing (2010, p. 342), each factory system should have an extension

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also for other transformations (e.g. system element replacements). Helbing (p. 243) recognises that FOs/FSs are mutually dependent, and claims (p. 90) that practical experience confirms that the replacement of one machine can lead to the requirement to move, rearrange and fix 20 others. Furthermore, Helbing (pp. 572–

580) discusses displacements of FOs/FSs that require spaces/rooms. An area-related and spatial dimensioning of FOs is also considered (p. 199), the same as a process-dimensioning through the consideration of FOs/FSs, pits, floor loads and numerous other area-related characteristics (pp. 232–235). Types and characteristics of different process flows (e.g. multiple coupled flows) (pp. 200–208) in combination with the other information in this paragraph provide a hint of both ‘changing transformation requirements’ and transformability requirements of areas and factory substructures.

That requirement-conforming machine-installation, ‘spatial-technical definitions’

and standardisations are crucial for a proper functioning of factories was indicated by Kettner, Schmidt and Greim (1984). According to Göpfert (1998), standardisations of technical modules and their interfaces can help to handle complexity and meet transformation requirements. The importance of standardised plug-in slots, interfaces and a flexibility in this regard have been recognised by Heger (2006). Nofen, Klußmann and Löllmann (2013, p. 17) argue that through the standardisation of technical modules and their interfaces it can be ensured that modules are easily scalable and exchangeable. Standardisations are considered by Heger (2006) due to their frequency of occurrence, while customisations can be ignored (p. 78); this is not advisable, as they are both relevant.

Standardised area-modules increase the transformation potential (Heger, 2006, p.

99). These area-modules are not real modules, but are rather area parcels. This is in line with Hernández (2002, p. 79), who claims that the production layout is the only spatial transformation object to which the modularity can be allocated, and that the spatial arrangement of areas that involve a homogenous function can be understood as an area module.

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Bergholz (2005, pp. 3–4) claims that the definition of an optimal transformability-degree is a challenge. He speaks about a trade-off between this transformability-degree and stability. Klemke (2014, p. 4) talks of an activation effort, while Westkämper and Zahn (2009, p. 14) argue that transformations should be performed quickly at the lowest possible cost. Factory structures should be independent (Heger, 2006, pp.

75–76). Hildebrand et al. (2004) argue that the modularity and mobility of factory structures are crucial requirements of factories. Nofen, Klußmann and Löllmann (2013, pp. 26–27) claim that modularity is the most important transformation enabler. Grundig (2015, p. 28) talks about a modularisation and standardisation of areas and elements within rooms that can be flexibly combined, the use of flexible industrial structures that are demountable and reusable, and a targeted oversizing of FOs/FSs. Schenk, Wirth and Müller (2010 p. 7) claim that the transformability of

“production facilities ... is becoming a top priority for modern enterprises”.

Workstations within transformable factories must be structure- and location-flexible (Schenk and Wirth, 2004, p. 136). Furthermore, production processes should neither be disturbed nor interrupted during a transformation; required production stops should be minimised (Grundig, 2015).

Wiendahl, Reichardt and Nyhuis (2015, p. 115) talk about “breathability” and

“utilization neutrality” with regard to “adaptive buildings”. Pre-tested and movable building modules are a requirement of transformable factories. Sufficient building height, high loading capacity of the supporting structure and large column grid spacings are, in addition to transformable façades, requirements of buildings (Hernández, 2002, pp. 141–144). Furthermore, the area should not be partitioned/segmented by interfering contours/structures such as columns and walls. Other interfering contours/structures are s&d facilities and infrastructure elements inside buildings (e.g. building control systems, extraction systems, ventilation shafts, water pipes and other media routes). The usable building area is more flexible for future transformations with regard to personnel, material and production flows without such disturbing contours/structures (Wiendahl, Reichardt and Nyhuis, 2015).

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Wirth, Erfurt and Olschewski (2003) have recognised the importance of the mobility of factories and buildings. Fink (2003) describes the need for flexible s&d infrastructure. In addition, the importance of mobile foundations has been indicated by Fink. Helbing (2010, p. 90) recognises that the relocation of FOs/FSs has become fashionable.

Wiendahl, Reichardt and Nyhuis (2014, p. 129), the VDI 5200 (2016) and Hernández (2002, pp. 71–74) claim that areas are immobile. Hernández (p. 79) claims furthermore that area-modularity is not possible. Wirth, Enderlein and Peterman (2000) do not consider the modularity and mobility of areas when discussing the inner and outer mobility of different FOs. The same applies to Enderlein et al. (2002, cited in Schenk, Wirth and Müller, 2014, pp. 216–217), Günther (2005) and numerous other authors. Transformations of sites/areas and substructures cannot happen by means of the active transformability of areas (to which access is denied) if terrestrial areas are used.

Hernández (2002) stresses repeatedly the importance of function- and utilisation neutrality, and argues that a preferably square-shaped area leads to utilisation neutrality. Furthermore, continuous area-neutrality (which means homogeneous soil condition and stability with no differences in level) is preferred. The arrangement of buildings and further FOs which can only be moved/relocated with huge effort should be done sensibly in order to preserve the transformability (p.

79). Heavy production facilities should be located at outer positions of the factory layout to create large utilisation-free (i.e. neutral) areas in the centre that are not restricted through fixed points. The importance of the linking ability – which reflects the main flow capabilities – has been partly identified, as Hernández recognises the requirement for a gapless supply network and system (pp. 143–144).

Nevertheless, Hernández (2002) concludes that the transformability of areas is not relevant in the light of required transformation scopes. The general structure and site(/area) are uncritical transformation objects, as both imply only minor transformation requirements (pp. 144–146). Hernández’ scenarios led to a factory solution that involves a TBS (pp. 145–146), which is shown in subsection 2.3.1.

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These statements were made based on a scenario-related application example that considers, compared to automotive OEM plants and similarly huge complex factories, a small simple factory. Furthermore, the number of key factors has been limited and a time horizon of seven years considered, which is a further simplification of the real complexity and related developments. Moreover, probability theory and the limited transformability of factories which decreases further over time have not been considered. Therefore, Hernández’ (2002) results have little to do with huge complex factories – especially over long periods of time.

Areas are not relevant to Hernández from a transformability perspective and this makes little sense if huge complex real-world factories such as numerous OEM plants and their developments are considered.

Wiendahl, Reichardt and Nyhuis (2009, p. 140) recognise that the transformability of the layout/general structure is required. Grundig (2015) emphasises that the area and general structure are important for the transformability of factories.

This subsection shows both that diverse statements are conflicting and that a

‘traditional terrestrial area-related way of thinking’ dominates factory planning. All transformability-related solutions have in common that potential future area-related transformation scopes must be predefined and reserved. Such reserves determine factory layouts. The importance and significance of the transformability of areas and factory substructures (and of the general structure) are far too underestimated, which directs factory planning. That terrestrial areas are taken for granted is probably one reason for this, and is why their transformability is not questioned appropriately.

2.2.9 Summary

Available factory planning theories provide important information and, to some extent, a good basis for further development.

That a transformation can negatively impact the transformability of today’s factories has been recognised. This is a problem if transformation requirements change during a project or afterwards. On the one hand, factory (implementations

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‘as is’- and ‘to be’-statuses of all FOs/FSs involved must be appropriately considered. On the other hand, transformations should start as early as possible, as the transformation velocity is low if terrestrial areas and/or rigid structures are significantly impacted. If a transformation, for instance, is performed with a line of least resistance attitude in which rigid objects and structures are the outcomes, changing transformation requirements (during a project or after its completion) cannot be processed and absorbed as required. The limited and furthermore decreasing transformability of today’s factories and permanent changes of the factory environment are consequently not sufficiently considered, and it is highly questionable whether these factors and their consequences can be handled appropriately with today’s factories. This is not sufficiently considered in the factory planning literature. Furthermore, the assessment and planning of ‘as is’- and ‘to be’-statuses of FOs/FSs, and of their ‘as is’- and ‘to be’-transformability is not sufficiently thought out, as it can neither be completely delimited nor completely combined – at least not within today’s factories where transformations significantly impact the transformability, or rather rigidity and inhibition.

Scenarios are used to define the ‘to be’-status(es) of a factory, which is hardly possible for huge complex factories. The ‘to be’-status(es) is required for all factory planning approaches and methods for the assessment and planning of transformability and of (implementations/)transformations, which leads to their poor operation. Furthermore, even if these scenarios, approaches and methods were to work, no considerable advantages could be gained, as the practice of factory planning is not sufficiently considered (e.g. the limited and furthermore decreasing transformability of today’s factories).

The question is how far the abovementioned approaches and methods can be improved at all when today’s factories are involved. Notwithstanding this, terrestrial areas have not been considered in factory planning theory in a way that is capable of showing their importance. Transformation requirements for areas have also not been sufficiently described, as is the case with the limitations of today’s factories and factory planning theories. These theories are relevant for

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practice, as they are used by factory planners. The new model may lead to advantages for both theory and practice.