Yalın üretim ve dijitalizasyon (endüstri 4.0 + endüstri 5.0): Çok boyutlu etkileşim matrisi ve üretim firmaları için kurulum, geliştirme stratejileri ve değerlendirme modeli
Lean+digitalization (Industry 4.0 + industry 5.0): Multi-domain matrix as a reference implementation and improvement strategies for manufacturing companies and assessment model
Yazar: HASAN OKTAY GÖKTAŞ
Danışman: PROF. DR. NEJAT YUMUŞAK
Sakarya Üniversitesi / Fen Bilimleri Enstitüsü / Bilgisayar Mühendisliği Ana Bilim Dalı / Bilgisayar Mühendisliği Bilim Dalı
Derece: Doktora, 2024
Konu: Bilgisayar Mühendisliği Bilimleri-Bilgisayar ve Kontrol = Computer Engineering and Computer Science and Control ; Endüstri ve Endüstri Mühendisliği = Industrial and Industrial Engineering ; Mühendislik Bilimleri = Engineering Sciences

Özet:
Üretim sektörü dijitalizasyon (Dx) (Endüstri 4.0 + Endüstri 5.0) ile beraber büyük bir dönüşüm yaşamaktadır. Bu dönüşümü çevik, verimli ve sürdürülebilir bir şekilde yapmak zorunluluğu ve güçlükleri yanında üretim sektörü yalınlığı (Lean) da sürdürmek zorundadır. Bu çalışma üretim sektörü için dijitalizasyon dönüşümü ve kurulumu yanında yalınlığı da sürdürmek ve dönüşüm ile beraber güçlendirmek için izlenecek stratejileri belirlemeye yardımcı olacak kritik başarı faktörlerini (KBF) , yalınlığı güçlendirme rotalarını, yalın+Dx çerçevesi için bir değerlendirme modelini, yalın üretim konusunda öncü kabul edilen bir üretim firmasının (Toyota Motor Europe)  bu dönüşüm sürecini deneysel olarak inceleyerek belirlemeyi hedefler. 

Dönüşüm sürecindeki KBF'leri doğru bir şekilde incelemek ve yalınlığı güçlendirme rotalarını belirlemek için öncelikle hem yalın hem de Dx için bütünsel bir bakış açısı sağlayacak tüm kavramları, ilkeleri, unsurları, yöntemleri, araçları ve türleri içeren bir çerçevenin oluşturulması gerekir. Bunun yanında her iki alan arasındaki etkileşimin tanımlanması ve değerlendirilmesi gerekmektedir. Bu amaçla, her iki alan için ontolojiler oluşturulmuş, alanlar arası bağlantılar çok boyutlu etkileşim matrisi olarak belirlenmiştir. KBF'ler "dijital dönüşüm" ve "yalınlığı sürdürme" başlıkları altında gruplandırılarak belirlenmiştir. Çalışmada Delphi metodu kullanılmıştır. Literatür taraması ile oluşturulan ontolojiler, çok boyutlu matris ve belirlenen kritik başarı faktörleri, Delphi metodunun ilk adımı ile uzmanlarla birebir yapılan oturumları takiben son haline getirilmiştir. Takip eden Delphi roundlarında, alanlar arasındaki her bir bağlantı için, "etkileşimin etkisi", "dijital dönüşüm" ve "yalınlığı sürdürme" kritik başarı faktörleri değerlendirilmiştir. 

Bu çalışma sonucu dijitalizasyonun yalınlığı pozitif etkilediği ve yalın düşüncenin (lean thinking) dijitalizasyonu ve dijital dönüşümü desteklediği sonucuna ulaşılmıştır. Değerlendirilen 12 etkileşim bağlantısnın 6 tanesi için "yüksek/güçlü pozitif etki" sonucu elde edilirken, 3 bağlantı için "yüksek pozitif etki" ve kalan 3 bağlantı için "orta pozitif" etki sonucuna ulaşılmıştır. 11 adet "dijital dönüşüm" KBF'si arasında ilk sırada "üst yönetim desteği ve dönüşümsel liderlik" yer almıştır. Bunu çalışan ve ekip çalışması ile ilgili 4 adet KBF takip etmiştir. 9 adet "yalınlığı sürdürme" KBF'si arasında ilk sırada "git ve gör prensibini koru (keep Gemba)" yer almıştır. Bunu "zamanında duruştan ödün vermeme (never comprimise Jidoka)", "yerinde kaliteyi koruma (keep and enforce JKK)" ve "insan dokunuşu ile otomasyon (keep automation with human touch)" takip etmiştir. 

Endüstri 4.0 dönüşümünü adresleyen kritik başarı faktörleri çalışılmıştır fakat bu dönüşüm sürecinde yalınlığı koruma kritik başarı faktörleri çalışılmamıştır. Endüstri 4.0 yanında Endüstri 5.0 paradigmasını adresleyen kapsayıcı çalışma bulunmamaktadır. Yalınlık ve dijitalizasyon arasındaki ilişkileri tanımlayan dijitalizasyonun yalın üretime etkisini değerlendiren ve bu süreçte yalınlığı sürdürme faktörlerini ve güçlendirme rotalarını belirleyen holistik çalışma bulunmamaktadır. Çalışmamız listelenen bu alanları adreslemektedir. 

Yalınlık ve dijitalizasyon alanlarında ayrı ayrı olgunluk değerlendirme modelleri bulunmaktadır fakat yalın+dijitalizasyon olgunluğunu konu alan, Endüstri 5.0 paradigmalarını da içeren bir değerlendirme modeli bulunmamaktadır. Çalışmamızın son bölümünde deneysel çalışmamızın sonuçları da kullanılarak, Yalın+Dx (Lean+Dx = LDx) organizasyon çerçeve modeli tanımlanmış ve bu model için bir olgunluk değerlendirme modeline temel olacak ana ve alt değerlendirme boyutları önerilmiştir.  

Bu çalışmanın sonuçları üretim firmaları, küçük ve orta büyüklükteki işletmeler (KOBİ) için dijital dönüşüm ve bu süreçte yalınlığı sürdürme ve güçlendirme için doğru stratejileri belirmeye yardımcı olacaktır. 

Çalışmamız kapsamında önerilen LDx modeli ve değerlendirme boyutları kullanılarak hem yalınlığı ve hem Endüstri 4.0 ve Endüstri 5.0 paradigmalarını içeren olgunluk değerlendirme modeli geliştirilebilecektir.

Son olarak, ontoloji yaklaşımını kullanarak Dx ve yalınlık organizasyon modellerinin ve bağlantılarının belirlenmesi, yalınlık ve Dx konusundaki teori tartışmasına yeni bakış açıları sunacaktır.

Abstract:
This study describes the critical success factors for digitalization in manufacturing within the framework of Industry 4.0 and Industry 5.0 while sustaining Lean and Lean-reinforcement links during this transformation within the actual transformation journey of an enterprise (Toyota Motor Europe). According to the findings, the main and sub dimensions of a maturity assessment model for the Lean+Dx model are also proposed.
Today, manufacturing faces the biggest challenges in its history. The first, second, and third industrial revolutions have taken place one after another whereas today the fourth   and fifth industrial revolutions are almost simultaneous. While embracing Industry 4.0 (I4.0) and Industry 5.0 (I5.0), manufacturing should also preserve its existing gains and philosophy which are formed under the term "Lean". "Lean" was coined in 1988, derived from the Toyota Production System (TPS). I4.0 was coined in 2011 and shortly thereafter, I5.0 was coined. While I4.0 addresses technologies, I5.0 addresses human, society, environment, circular economy, resiliency, and the boundaries of the planet. These emerging values are not directly addressed by I4.0 paradigm. It is also important to understand the significant shift from a technology-driven I4.0 to the more human-centric driven I5.0. 
As manufacturing has been implementing technology-driven I4.0, I5.0 began to be understood as a paradigm that recognizes the power of the industry to achieve societal goals beyond jobs and growth. It aims to become a resilient provider of prosperity, by making production respect the boundaries of our planet and placing the wellbeing of the worker at the centre of the production process. In 2015, the United Nations General Assembly (UNGA) created the "Sustainable Development Goals" SDGs. In 2021, the European Union (EU) formally called for I5.0. Globally, many countries have introduced similar strategic initiatives: National Strategy for Advanced Manufacturing (USA), Society 5.0 (Japan), and Made in China 2025 (China). Regardless of the name, I5.0 paradigm is a reality. Therefore, in digital transformation, manufacturing should also consider the I5.0 paradigm, its concepts, mandates and expectations introduced by policymakers and society alongside the I4.0 technical framework. It can be said that I5.0 is the key enabler and mandate of digitalization (Dx) next to I4.0.
There are numerous challenges introduced by I4.0 and I5.0 that also need to be considered by Lean philosophy and practices. 
Manufacturing is being transformed by technologies and is becoming more connected and data-driven. With digitalization, cybersecurity has become a key concept in sustainability. Innovation is key to survival in today's rapidly changing market. The manufacturing need for new skills (both technical and transversal) introduces 
significant challenges to the education system and manufacturing including personalized education. Just in time hiring strategies need to change radically to form closer collaborations between manufacturing and education (joint programs, hybrid education). Privacy and data protection regulations impose strict rules and companies may face significant  fines. Human-robot co-working (cobot) is a challenging task for enterprises. Moreover, human augmentation technologies such as wearable devices, robots, and eyeglasses may go beyond ethical dilemmas and be subject to regulations. With the COVID-19 pandemic, companies began to recognize the value of digitalization, knowledge integration in both horizontal and vertical directions for agility, quick reaction to customer expectations, and adaptation to new business models.
Societal megatrends require workforce diversity.  In the meantime, the aging work-force needs to be reskilled and upskilled.  Companies' efforts to reach new talent, introduce more diversity into the workforce where company culture should be ready for it. Innovation and human centricity have been identified as key concepts of digitalization in many articles and are well received by policymakers. The rapid proliferation of new technologies will continue to transform roles within manufacturing such as data scientists, compliance officers, collaborative robot experts, and virtual operators. Overall, these efforts imply more investment in  the workforce and society.  The environment and circular economy paradigm are becoming increasingly relevant as companies realize  the real value and profitability of this new, sustainable way of doing business. It relies on several strategies to extend the product life cycle through reusing, recycling, remanufacturing, and redesigning circular products and materials. Sustainability, resiliency and the circular economy are key challenges that manufacturing companies should  manage and develop strategies for their products and business models. 
All of these changes include regulations introduced by policymakers, societal realities, expectations that manufacturing should consider for sustainability and resiliency. 
The term "Lean" refers to a state of the art level in manufacturing. Lean principles or TPS philosophy cannot be addressed by the I4.0 paradigm alone. Key terms of TPS, Toyota Way philosophy such as "Waste Reduction", "Levelled Production", and "Respect for People" have definitions under the I5.0 paradigm. Toyota aims to undergo Dx transformation while reinforcing Lean and considers Dx as a combination of I4.0 and I5.0 frameworks. Digital transformation is inevitable but Lean philosophy should be sustained.
For TPS or Lean visualization, the two-pillar temple model is a very popular form used in many studies. However, this model  often leads people to understand Lean as a toolbox from which to choose the appropriate "tools". However, Lean  is not a toolbox; it is a philosophy for manufacturing.  "Lean thinking" is another widely used term in literature to emphasize the management framework of Lean made up of a philosophy, practices and principles. For our research, we need a better representation of Lean that  shows all its aspects and allows us to define relations to the digitalization paradigm. "Ontology" allows us to show concepts, principles, elements, methods, and tools with synergistic links and philosophy.  Having a holistic conceptualized view will allow us to identify the relations (multi-domain matrix) between Lean and Dx accurately for impact evaluation and to assess Lean reinforcement points and allow experts  to evaluate critical success factors (CSFs) more meaningfully with the visual representation.
Considering our research topic, the level of perfect Lean understanding, digital transformation experience and short to long term business, technology and environmental vision are key prerequisites for the panel members. The survey needs to be conducted with experts and opinions need to be aggregated. A survey with these experts was conducted, in which the Delphi method was used as a survey tool for an analysis, which was performed in three steps: an analysis of psychometric properties was conducted, a stability analysis of the Delphi method was performed, and the significance of non-consensus hypotheses of the results were examined. 
The following list summarizes the key research objectives:
1.	Identification and validation of Lean reinforcement links.
2.	Identification and validation of CSFs-DT (digital transformation) to have agile, successful Dx transformation.
3.	Identification and validation of CSFs-LS (Lean sustainability) to sustain Lean while transforming to Dx.
4.	Propose managerial implications for agile and sustainable Dx transformation while reinforcing Lean.
5.	Proposal of main and sub dimensions for Lean+Dx (LDx) assessment model based on our results.
In this regard, 12 reinforcement links (between Lean and digitalization), 11 critical success factors for "digital transformation", 9 critical success factors for "Lean sustainability" were identified from the published literature and 56 one-on-one discussions with Toyota Production System experts. Both Lean and digitalization frameworks were developed using the ontology method.
The results show that "top management commitment" is the most critical factor for digital transformations, whereas for Lean sustainability, it is "keep Genchi Genbutsu (go and see)". It was found that digitalization impacts Lean very posi-tively (high/strong or high) for a majority of the links and lean on the positive side for the remaining links.
Studies have examined critical success factors for implementing Industry 4.0 technologies from organizational and transformational aspects, or for specific areas such as project management, or with a focus on a particular technology implementation. Some studies have also looked at CSFs for I4.0 technology implementation while considering some Lean principles. Additionally, some studies have included CSFs from Industry 5.0. However, none of these studies have examined a comprehensive list of CSFs for all concepts of I4.0 and I5.0. No study has explored the CSFs for a company to sustain a Lean framework while transitioning to Dx. Our study aims to identify CSFs for both Dx transformation and Lean sustainability, as well as to validate relations between Lean and Dx within the context of I4.0 and I5.0 paradigms to identify Lean reinforcement links.
There are assessment models for Lean and Industry 4.0. However, there is not an assessment model for both Lean and digitalization including Industry 5.0 paradigms. In the last part of our thesis, using the empirical study results, an organizational framework has been proposed that covers both Lean and Dx (I4.0 + I5.0) named as LDx, and main and sub-dimensions of a maturity model have been listed which would be a base for an assessment model for LDx framework.
This contribution shall serve as an essential basis for manufacturing companies and Small to Medium Enterprises (SMEs) for their Dx transformation while sustaining and reinforcing Lean with minimum cost, lead time, and having the right strategy.
By using the proposed LDx framework and maturity model dimensions, an assessment model for both Lean and I4.0 plus I5.0 can be developed.
Lastly, the formalization and development of Dx and Lean organization frameworks using the ontology approach and the identification of reinforcement links would offer new insights and perspectives on the theory discussion of Lean and Dx.