# Lean and Flexible Project Delivery
## 5 Contributions and Conclusions  
The main result and contribution is the proposed operational system, with options for flexibility implemented into master control schedules within the frame of lean project  
Figure 4: Decision tree with high belief in stable demand (\(p=0.9\)). delivery, along with test results to evaluate the value of planned flexibility, as laid out in Sections 3 and 4. The solution enables the combinative capabilities of lean efficiency through waste reduction and flexibility to pursue objectives and implementation pathways that may change during the course of the project. This section concludes with insights this research provides to managing complex dynamically changing projects. (1) The insight the multidisciplinary DSR provides to the management of ETO and construction projects: It is stated that future project management research needs dynamic and agile approaches that are effective responses to real challenges, and that make academic research more relevant to practice [33]. The research presented here demonstrates how to make model-based research more relevant to practice, and more relevant for project management processes associated with learning. Further, we demonstrated the agility and dynamic capabilities of DSR to develop new knowledge for the management of project uncertainty. These capabilities are achieved by learning loops of build-evaluate., until a customized planning solution to a particular field project is achieved ('customized' in the sense of the chosen level of flexibility, aligned with performance measures agreed upon in collaborative front-end phases). We know that higher levels of flexibility enable improved adaptability, but this comes with additional costs. We also know that lower levels of flexibility may nearly capture the benefits of full flexibility [48]. However, what is the 'right' level of flexibility? An exact answer is difficult to obtain in complex projects. Model-based research has helped to improve understanding on what flexibility is appropriate in different circumstances, but these are difficult to apply in practice. What practitioners can do is to apply DSR to quickly build-evaluate. different levels of flexibility before the decision is taken. The guidelines to follow in this process are provided in Section 3. The methods and tools to apply within these steps may vary according to the means available to a particular field project. For example, we propose uncertainty assessment by the impact of a change in system perspective, disregarding change probabilities [76], but other methods may be more appropriate in a given context. (2) The insight the proposed planning approach provides to the management of lean projects. We highlight three main aspects of the results: (i) Guidelines professionals can use to customize their lean construction practices to uncertain contexts, consisting of component processes for pull planning, uncertainty assessment by assessing the impact of changes disregarding their probabilities, and incorporating options into the project milestone schedule (described in Section 3). (ii) Guidelines to evaluate quantitatively whether the project with a chosen level of flexibility can be delivered within performance measures agreed upon (described in Section 4). This is also related to project and business case validation. (iii) Guidelines to explore the value of planned flexibility for capturing opportunities resulting from customer-driven changes (as shown by the case in Section 4.2). The practical relevance and external validity of this research is increased by the wide adoption of LPS(r) in the AEC industry, and increasingly in ETO projects, such as shipbuilding, as a mechanism to implement lean construction. Limitations and future research direction: The research is a proof of concept of the proposed operational planning solution, to illustrate the potential gain from the proposed solution.