# Lean and Flexible Project Delivery
## 4 Discussion--The Utility of the Proposed Operational System
### Utility Evaluation Using a Real Case  
We built on the Hospital Building Project in [61] to demonstrate the expected gain if flexibility was implemented into the applied lean project delivery solution. We do not replicate that case but provide a different way of analyzing the results, including decision trees. The case makes use of the true lean master plan developed by pull planning, as described by a lead practitioner involved in that process [61]:  
_\"We had enabling work in this project. We did pull planning, but it didn't become a primary driver of the job. In XX hospital project we had to literally move a mountain (700,000 CY of earth) before we could start construction. This was considered as an enabling project so it gave the designers ample time to get the project developed so design would not impact our construction schedule. However, our schedule process was as follows: We developed a Master Schedule or what we called a Validated Target Schedule (VTS) at the initial alignment meeting when YY conducted our offsite Business Case validation meeting. Next, we developed a Pull Schedule from the major milestones off the Master schedule with the major trade contractors. Then we refined the schedule as the design developed and conducted weekly work plans with the people or leaders of the teams that actually performed the work. We only tracked PPC, but we did our learning from our weekly analysis of our PPC and discussions stemming from that data at our weekly work plan meetings.\"_  
Options implemented into the pull plan are hypothesized, based on uncertainties that have, and could have, impacted the project (knowable unknown-unknowns). These are listed by lead practitioners, as follows: change in site location, change in dental equipment, change in surgery suite design, and change in pharmacy pick system design. For our scope, change in dental equipment (type and quantity of chairs) is chosen. This change is driven by uncertainty in demand for dental services in the hospital region and is expected due to market (demography) uncertainty, although the exact type and size of change is difficultto predict. This uncertainty is estimated to be revealed far into the Construction and Prefabrication phase, which takes 413 days, following the Team Selection and Alignment Process phase of 349 days, and the Design phase with 229 days. The last phase, Commission and Inspect, takes 88 days. We assumed two possible demand outcomes: stable (with an estimate of 10 dental chairs) and increase due to expected demographic changes (up to doubled demand, implying 20 dental chairs). This represents an opportunity. Following the planning process in Section 5, the option \"Delay of the decision on the dental equipment type and quantity, until relevant demand information is obtained\" was implemented into the lean master plan. This option carries the mutually dependent sub-options: (1) shell option, to prepare the foundation and floor plan to enable late installation of different types and numbers of chairs (increase space, specify easily removed flooring to install equipment support and others); (2) option contract for a commitment from suppliers to reserve capacity for dental equipment up to the increased demand level. The question to answer for a decision maker is: (i) should the project continue with the current estimate for dental equipment, which is 10, and accept unsatisfied demand in case of increase (deterministic lean approach), or (ii) should it react only if a change occurs, with an update that requires revising multiple project phases with collateral impacts (time, money, and project momentum) on surrounding construction (reactive lean approach)? Or (iii) should the option be implemented into the project plan to enable timely and cost-efficient reaction to demand increase (proactive lean approach)? Under (assumed) known demand, all decisions are fixed early (call it D).