Shared CityWater premises

CityWater 2027 is a fictional utility with twelve pumping stations in two service areas. A and C are in North; B and D are in East; the other eight stations supply the remaining capability and are unchanged by the compared options. A, B and D have abnormal vibration. Existing, case-supplied diagnostic accounts distinguish their conditions and support the particular interventions below; the vibration label alone supplies neither diagnosis nor a life estimate.

The case supplies an existing water-delivery mandate issued by CityWater’s water-service authority. It requires water of the stated quality and minimum delivered North/East rates of 700/700 m³/h during the dry work window and 1,100/900 during the wet season. The case assigns revision of this mandate to the water-service authority; the infrastructure committee chooses the asset programme within it.

Separately, the supplied operating account gives normal usable North/East capability of 1,000/1,000 m³/h. The wet-season North requirement exceeds present usable capability by 100 m³/h. Both shortlisted C options add 200 m³/h, either by modification or by a qualified leased service. The 200 is the contribution of these options, not an unstated minimum increment. During a dry-window outage, A removes 200 from North and C removes 300; B and D each remove 200 from East. One A or C outage fits the dry requirement, but their simultaneous outage gives only 500 and does not. Simultaneous B and D outages leave 600 in East and also fail. These are finite supplied service bounds, not a hydraulic model or a probability of reliability.

The case additionally supplies applicable engineering and service-risk qualifications for each shortlisted policy, including the supported fallback and response to abnormal conditions. Their boundaries cover the stated duty and horizon. No claim about every contingency or a new real equipment limit is derived from the simple supply totals. If a qualification is absent or invalidated, EAM.9 removes that option from the eligible comparison and returns the missing specialist question. Lower financial cost does not repair the missing qualification.

The comparison horizon is the five years beginning with the initial 2027 decisions. All values are constructed millions of constant-price euros, from the utility’s stated perspective. The real discount rate is 3% solely for this example. Initial capital and initial operating cash occur at time zero; recurring costs occur at each year end; residual value occurs at the end of year 5. The supplied terminal values represent remaining service value, net of the stated exit costs, on the same basis for every option. A different sale/withdrawal decision needs its own terminal-value basis. Different technical lives do not disappear at the five-year boundary.

The annual amounts include the specified energy, routine maintenance, inspection, contingent response and continuing service costs under each policy; do not add them again as a separate generic risk allowance. A material unpriced consequence remains outside the sum and must retain its own criterion. Historical expenditure is sunk for this future choice. Accounting depreciation is not an additional cash outflow. Financing and tax effects are held equal in this constructed comparison; a real difference would require explicit treatment by its supplying practice.

Define a = Σ(t=1..5) 1/(1.03)^t = 4.579707187 and d = 1/(1.03)^5 = 0.862608784. For each option, present cost = initial capital + initial operating cash + annual cost × a − terminal value × d.

Each duration includes the required isolation, intervention, testing and return for that option, using one already qualified and available team. Prerequisite design, procurement and non-outage preparation are supplied as complete before the window. Days denote the same staffed whole-work windows in both the calendar and the estimates; they are not individual person-days. These are teaching inputs, not equipment procedures or industry duration norms. For a real case, use the MNT.7 result rather than assuming those inclusions.

The D continued-use policy is a supported five-year service policy with the specified initial maintenance intervention, recurring maintenance, response and backup provisions. It is not an unsupported extrapolation of a one-year condition forecast. The case’s qualification is conditional on unchanged duty and the identified failure mechanism; a new structural finding invalidates it. No new diagnosis, repair effectiveness or permission is inferred from the economic calculation.