Supply chain disruptions

A pharmaceutical commercial-supply build is a long, regulated, fragile chain exposed to API sourcing, manufacturing and a regulatory PAS - any of which can stall the launch. With six discrete disruptions in play, the first question is not "when?" but "which disruptions own the schedule risk?" This case study runs a Tamara schedule-risk model of an 11-activity supply build-and-qualification programme to rank them.

Discrete risk events - expected schedule impact (probability x delay)

The discrete-risk Pareto is the headline. API shortage/supplier slip tops it at 7.3 expected weeks of delay (27% of the total) and single-source disruption adds 6.1 weeks (23%) - together 49% of the expected discrete-risk delay sits in just two events, both on API supply. The cumulative line makes the case for concentrating dual-sourcing and safety-stock effort there; the top five of six events carry ~80% of the delay.

The model

Eleven activities with three-point PERT durations on a critical-path network, plus six discrete supply-chain risk events - API shortages, single-source disruption, equipment failure, batch failures, QC investigations and a regulatory PAS query. One Monte-Carlo of 60,000 iterations drives every chart.

Two API events own 49% of the delay risk

The Pareto's message is concentration: the two API-supply events alone account for nearly half the expected discrete-risk delay, far ahead of regulatory retest (4.1 weeks) and batch failure (3.7 weeks).

How the stages phase

Stochastic Gantt - P50 bar with P10-P90 finish spread per activity

The Gantt shows the supply build sequence. API qualification and procurement carry the widest bands and sit at the front of the chain - their slippage pushes everything downstream.

API procurement drives readiness at 0.72 cruciality

Schedule tornado - which stage drives the supply-readiness date

The tornado confirms the Pareto from the duration side: API procurement and delivery dominates at a cruciality of 0.72, far ahead of the regulatory PAS (0.43) and API supplier qualification (0.26). The single most disproportionate driver is the API line - exactly the dependency a single-source supply chain is most exposed on.

Mitigation cuts overrun probability from 33% to 7%

Supply build cost distribution - impact of mitigation

Cost is schedule-linked: every day past plan carries about $0.10M of expedited freight and idle-capacity overhead. Before mitigation the cost mean is $167M with a P90 of $197M against a $176M budget - a 33% overrun chance. The mitigation case (dual sourcing, safety stock, parallel batches) pulls the mean to $151M and the P90 to $172M, cutting the overrun probability to 7% and the P80 finish from 1,203 to 1,093 days.

The supply-readiness date spread

Supply-readiness date distribution - the tail the top disruptions create

The finish distribution closes the loop: a right-skewed readiness-date spread with a P50 of 1,089 days, a P80 of 1,203 and a P90 of 1,267 days - 377 days beyond the 890-day deterministic plan, the tail those two dominant API events create.