Supply Chain Optimization
Follow the product from raw material to customer, find the node that's broken, and price the fix.
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The gist
- →Lay out the actual chain the product travels (Plan-Source-Make-Deliver-Return / SIMDC) and walk it node by node instead of jumping to a fix.
- →Attach two numbers to every node, cost per unit and days, then benchmark to find the one broken node that constrains the whole chain.
- →Every lever trades off cost vs service vs cash: cheap sourcing lengthens lead time, faster delivery costs money, higher fill rate needs non-linearly more stock.
- →Stockouts are rarely an inventory-quantity problem; check the demand signal (bullwhip, forecast) and lead time first, then size the fix in rupees on contribution margin.
The framework at a glance
When to use it
Reach for this framework whenever the case prompt describes a physical flow that is failing rather than a market that is shrinking. Classic triggers: "our stores keep running out of the fast-moving SKUs while the warehouse is full of slow ones", "our delivery lead time is 12 days and the competitor does 4", "working capital has ballooned and inventory is 70 days", "freight is now 7 percent of sales and rising", "should we open a second plant / consolidate our 22 depots into 6", "a key supplier just went down and we lost three weeks of production", "should we make this in-house or outsource it", "our on-time-in-full is 78 percent and the retailer is fining us". It is also the right lens inside a broader profitability case once you have traced the problem to the cost side and found it sitting in COGS, freight, warehousing or write-offs — at that point stop using the profitability tree and switch to walking the chain. Do not use it when the real issue is demand, positioning or willingness to pay: a product nobody wants does not become a good product because you shipped it faster.
What it is
Supply Chain Optimization is not one formula. It is a way of laying out a business as a physical chain of steps that a product actually travels through — supplier, inbound freight, factory, warehouse, distributor, retailer, customer — and then asking, node by node, where money is leaking, where time is being lost, and where the chain breaks under stress. The consulting version of this is usually taught as the SCOR model (Supply Chain Operations Reference, maintained by ASCM), which chunks any supply chain into Plan, Source, Make, Deliver, Return, plus an Enable layer for the data, contracts and governance that hold it together. Case-interview coaches teach a slightly friendlier version of the same idea with the initials SIMDC: Suppliers, Inputs, Manufacturing, Distribution, Customers. Both are doing the identical job — forcing you to walk the chain in order instead of jumping straight to a favourite answer.
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The reason the framework exists is that supply chain problems almost never show up where they are caused. A retailer sees empty shelves and concludes it needs more inventory. In reality the stockout may be caused by a forecast that is wrong at SKU level, a supplier whose lead time quietly drifted from 14 to 28 days, a plant that runs huge batches because changeovers take six hours, or a depot network laid out for a tax regime that no longer exists. Every one of those has a different fix and a different cost. Optimization means finding the constraint — the one node that actually governs the performance of the whole chain — and improving that, because improving anything else changes nothing. This is why supply chain thinking is closer to detective work than to a checklist.
The second thing that makes this framework distinctive is that it is explicitly about trade-offs, not about a single number going down. Every supply chain sits somewhere on a three-way tension between cost, service and cash. Cheaper sourcing usually means longer lead times, which means more safety stock, which means more cash locked up and more obsolescence risk. Faster delivery usually means air freight or more warehouses, both of which cost money. Higher service levels — a 98 percent fill rate instead of 95 percent — require disproportionately more safety stock, because the relationship is non-linear. A strong answer in a supply chain case never says "reduce cost". It says which of the three the company is choosing to buy, what it is paying, and whether that price is worth it for this business.
How to apply it, step by step
- 1
Draw the physical chain end to end before you structure anything
Out loud, name every node the product passes through and every party that touches it: raw material supplier, inbound transport, plant, primary freight, regional depot, distributor, retailer, end customer. Ask the interviewer to confirm it, because half of them will correct you and hand you the answer. This picture, not a generic bucket list, is your framework — everything after this hangs off it.
- 2
Attach two numbers to every node: a cost and a time
For each step ask what it costs per unit and how many days it takes. Cost per unit builds up the landed cost so you can see which node owns the money. Days build up the total lead time and, separately, days of inventory sitting at that node. If the interviewer gives you data, this is what you should be asking for. A chain with numbers on it is a diagnosis; a chain without numbers is a drawing.
- 3
Benchmark and find the broken node
Compare each node against a peer, against the company's own past, or against another region of the same company. The node with the biggest unexplained gap is your suspect. Useful comparisons are freight as a percent of sales, days of inventory, on-time-in-full or fill rate, capacity utilisation, first-pass yield and cost per tonne-km. Say explicitly which node you are betting on and why — interviewers reward the commitment.
- 4
Separate a demand-signal problem from a physical-flow problem
Before fixing pipes, check whether the company knows what to make. Ask about forecast accuracy at SKU-location level, how often planning runs, and whether sales, marketing and operations use one number or three. If orders upstream swing far more than actual consumer demand, you have the bullwhip effect, and no amount of warehouse optimisation fixes it — the fix is sharing point-of-sale data, shrinking order batches and reviewing promotion-driven forward buying.
- 5
Find the root cause inside that node, not just the symptom
Long lead time at a supplier could be distance, MOQ, capacity, or the company's own late purchase orders. High inventory could be safety stock for volatile demand, batch sizes driven by long changeovers, or dead stock from a SKU tail nobody has pruned. Push two or three whys deep. The symptom tells you where to look; the root cause tells you what lever to pull.
- 6
Size the prize before proposing anything
Convert the gap into rupees. Recovered sales equals lost volume times contribution margin, not times price. Freight savings equals the percent-of-sales gap times revenue. Inventory reduction equals days saved divided by 365 times COGS, which is a one-time cash release, and the recurring benefit is that cash times the cost of capital plus avoided obsolescence. Stating the number is what separates an operations answer from an operations recommendation.
- 7
Generate levers and check the trade-off each one creates
Typical levers: consolidate the supplier base and renegotiate, dual-source the risky input, move production closer to demand or to a contract manufacturer, redesign the depot network, cut changeover time so batches can shrink, rationalise the SKU tail, shift service levels by segment, move from push replenishment to demand-pull. For every lever, name what gets worse. Nearshoring cuts freight and lead time but usually raises unit conversion cost — say so before the interviewer does.
- 8
Recommend with sequencing, a number and a risk
Close with one or two moves, the rupee impact, how long they take, and what could go wrong. Split quick wins that need no capex (SKU rationalisation, service-level segmentation, order-batch changes) from structural moves that do (a new plant, a redesigned network). Name the biggest risk and one thing you would check with more data — usually SKU-level demand variability or a supplier's true capacity.
Worked example
Bharat Bites is a packaged namkeen and snacks company with revenue of Rs 2,000 crore. It manufactures at two plants, Rajkot in Gujarat and Kanpur in Uttar Pradesh, and distributes through 21 carrying-and-forwarding depots to about 6,00,000 kirana outlets and a growing quick-commerce channel. The CEO's complaint: in South and East India, on-shelf availability is 82 percent against 94 percent in the North, yet company-wide inventory has climbed to 58 days and freight has reached 6.2 percent of sales versus a peer benchmark of 4.5 percent. Distributors are asking for more stock; the CFO is refusing because working capital is already stretched. Should the company build more inventory?
Draw the chain and localise the problem
The chain is: agri and packaging suppliers, inbound freight to plant, Rajkot or Kanpur production, primary freight to a CFA depot, secondary freight to a distributor, then to the kirana or dark store. Both plants are in the North and West. South and East are served entirely by primary freight of 1,600 to 1,900 km from Rajkot. Immediately the problem localises to the Deliver node for two regions, not to the Make node and not to demand.
Put cost and time on every node
Replenishment lead time to a southern depot is 9 days door to door against 3 days in the North. Primary freight to the South costs roughly Rs 3.10 per kg against Rs 0.90 per kg in the North. Southern depots hold 34 days of stock versus 19 in the North and still stock out, because the stock they hold is the wrong mix — long lead time forces them to guess the SKU split nine days in advance.
Diagnose the root cause
This is not an inventory-quantity problem, it is a lead-time and variability problem. Safety stock scales with the square root of lead time, so a 9-day pipeline needs about 1.7 times the buffer of a 3-day pipeline for the same service level. Compounding it, the plant runs 8-hour changeovers, so it produces each SKU in large infrequent campaigns; a southern depot that misses a campaign waits weeks. Ordering more of everything would raise inventory and obsolescence on a 6-month shelf-life product without fixing availability.
Size the prize
South and East are about 35 percent of revenue, or Rs 700 crore. If roughly half the 12-point availability gap converts to lost sales, that is about 6 percent of Rs 700 crore, or Rs 42 crore of revenue, and at a 22 percent contribution margin about Rs 9 crore of profit. The freight gap of 1.7 percentage points on Rs 2,000 crore is about Rs 34 crore. Cutting company-wide inventory from 58 to 45 days on COGS of Rs 1,300 crore releases roughly Rs 46 crore of cash one time, worth about Rs 5 crore a year at a 10 percent cost of capital, plus lower write-offs.
Choose the lever and name the trade-off
The structural fix is to move production closer to demand: appoint a contract manufacturer near Hyderabad for the six highest-volume SKUs, which are about 70 percent of southern volume. That removes 1,700 km of primary freight on the bulk of the tonnage and cuts depot replenishment lead time from 9 days to 3, which alone cuts required safety stock by roughly 40 percent. Trade-off: co-packing costs about 6 to 8 percent more per kilogram in conversion cost and adds a quality-control burden, so it must be tested against the freight and working-capital savings. Quick wins alongside it: prune the SKU tail that ships south, and set differentiated service levels so the top 20 SKUs get 98 percent fill rate while the tail gets 90 percent.
Recommend
Do not fund a blanket inventory increase. Over the next two quarters, sign a southern co-packer for the top six SKUs and rationalise the southern SKU list; expect roughly Rs 20 to 25 crore of freight and working-capital benefit and a recovery of most of the availability gap. In parallel, run a changeover-reduction programme at Rajkot so batch sizes can fall. Revisit the 21-depot footprint separately — post-GST there is no longer a tax reason for state-wise depots, and consolidation may be a further Rs 10 crore. Main risk to check with data: whether southern demand variability is genuinely high or is an artefact of distributors ordering in large batches.
Takeaway: The complaint was stockouts and the instinctive answer was more inventory. Walking the chain showed the binding constraint was distance-driven lead time, and the real fix was network design, which improved availability, freight cost and working capital at the same time instead of trading one against another.
More worked examples
Worked example: Toyota and the 2021 semiconductor shortage+
Through 2020-21 the global auto industry lost roughly 7.7 million units of production because it could not get semiconductors; industry analysts put the revenue impact at around 210 billion dollars (widely reported estimates, approximate). Almost every carmaker was hit, but Toyota kept building for several months longer than its peers before finally announcing a roughly 40 percent cut to its September 2021 global plan. Toyota was the company most identified with just-in-time, the philosophy that says inventory is waste, and yet it was the one holding chips. Walk the chain and work out why the company with the least inventory in the world was the one that had the right inventory.
Chip lead time, pre-COVID to late 2021
~13 wks to 20+ wks (approx.)
Semiconductor content per vehicle
~$500, ~2% of BOM (approx.)
Contribution at risk, Sept 2021 cut
~$1.8bn for one month (illustrative)
Annual carrying cost of a 3-month chip buffer
~$90-150m (illustrative)
Industry output lost, 2020-21
~7.7m units (reported estimate)
Draw the physical chain end to end, and refuse to stop at tier one
For a single automotive microcontroller the chain is: silicon wafer maker, foundry (a Renesas fab such as Naka, or TSMC), then assembly-test-and-packaging houses concentrated in Malaysia and the Philippines, then the chip company that sells the finished part, then a tier-one module maker like Denso, Aisin or Continental, then Toyota's assembly plant, then the dealer. Toyota's purchase order goes to Denso for a body-control module. The node that failed sat three tiers upstream and did not appear on any Toyota contract, which is exactly the lesson Toyota had already learned after the 2011 Tohoku earthquake, when it could not name who made the chip inside a wiper motor. Drawing the chain past your direct supplier is the whole game here; a candidate who stops at Denso never finds the constraint.
Attach a cost and a time to every node
An automotive-grade microcontroller takes roughly 26 weeks of irreducible physical process to produce: about 12 to 16 weeks in the fab, plus test, qualification and packaging. Industry lead times stretched from around 13 weeks before the pandemic to over 20 weeks by late 2021, with some automotive MCUs quoted close to a year (approximate industry figures). Now the killer ratio: semiconductor content is roughly 500 dollars on a vehicle with a 30,000 dollar average price, so about 2 percent of the bill of materials gates 100 percent of output. Toyota's own assembly node was never the problem, it holds about two hours of parts at the line and ran fine; the constraint was a cheap, small, long-lead, single-sourced component.
Separate the demand-signal problem from the physical-flow problem
Automakers cut chip orders hard in Q2 2020 on a forecast that vehicle demand had collapsed, then demand rebounded within months and they tried to reinstate orders. Foundries had already reallocated that wafer capacity to consumer electronics, which was booming, orders in larger volumes and pays more per wafer. Autos are only around 8 to 10 percent of global semiconductor demand, so the industry is not the priority customer when capacity is scarce. This is a textbook bullwhip amplified by a capacity-allocation reality, and it means no amount of plant scheduling, logistics or warehouse work would have fixed it.
Find the root cause of Toyota's difference, which is a deliberate purchase of resilience
After 2011 Toyota built a multi-tier supplier database mapping parts several levels upstream, and required suppliers to hold buffer stock of roughly two to six months on about 1,200 risk-flagged parts, semiconductors among them (as reported at the time, approximate). That is not a violation of just-in-time; it is just-in-time applied selectively, with the buffer bought precisely where the part is cheap, non-perishable, long-lead and capable of stopping the entire line. Toyota also had the multi-tier map, so when the Renesas Naka fab caught fire in March 2021 it could see which of its own vehicles were exposed within days rather than weeks. The competitive advantage was information first and inventory second.
Size the prize, on contribution and not revenue
An unbuilt vehicle is not lost revenue, it is lost contribution, so use roughly 15 to 20 percent of a 30,000 dollar average price, about 5,000 dollars a unit (illustrative). Toyota's September 2021 cut of roughly 360,000 units below plan therefore put on the order of 1.8 billion dollars of contribution at risk in a single month. Now price the buffer that avoided that for the earlier months: three months of chips at 500 dollars a car on a 9 million unit annual build is about 1.1 billion dollars of inventory, costing perhaps 90 million dollars a year at an 8 percent cost of capital plus some obsolescence risk. Paying roughly 90 to 150 million a year to protect something worth 1.8 billion a month is not a close call, and stating it in those terms is what turns an operations observation into a board-level recommendation.
Generate levers and name what each one costs
Four levers, each with its price. One, multi-tier mapping and risk-scoring parts on criticality times lead time times single-sourcing, then buffering only the top decile: cheap, but it requires suppliers to disclose their own suppliers, which they resist. Two, chip commonisation across platforms so one MCU serves many models: cuts variety and raises the pooled buffer's efficiency, but slows feature differentiation and locks the design. Three, contract directly with the foundry instead of through the tier-one, which Toyota and Denso effectively did by backing TSMC's Japanese fab venture from late 2021: it buys allocation priority but is multi-billion-dollar capex with a long payback. Four, spec flexibility, building and shipping vehicles with a feature deferred and retrofitted later, which is fast and free but degrades the customer experience and creates a rework tail.
Recommend with sequencing and a risk
Immediate, no capex: extend the multi-tier map to every part with lead time above 12 weeks, and set buffer targets by risk score rather than uniformly, since buffering everything would destroy the working-capital advantage that justifies just-in-time in the first place. Medium term: commonise microcontrollers across platforms and dual-source at the fab level, not just at the tier-one level, because two tier-ones buying from the same fab is not dual sourcing. Long term and capex-heavy: equity or long-term-agreement positions in foundry capacity, justified only if the option value of allocation priority beats the cost of capital across a cycle. Biggest risk: buffers on chips age badly against 6 to 8 year model lifecycles and design refreshes, so the buffer policy needs an obsolescence review, and the one datapoint to demand is true sub-tier capacity by part, not the tier-one's assurance that supply is fine.
Takeaway: Just-in-time did not fail; uniform just-in-time would have. The framework's discipline of walking past tier one and attaching a lead time to every node shows that the binding constraint was a component worth 2 percent of the bill of materials with a 26-week process time and no visible second source. The correct move is to segment parts by criticality times lead time times sourcing risk and buy buffer only where the option value dwarfs the carrying cost, which is a policy decision about which of cost, service and cash you are buying, not a warehouse decision.
Worked example: a D2C ethnic-wear brand losing money to returns (Indian case interview)+
Kiara Label is a four-year-old D2C women's ethnic-wear brand selling through its own website and app. It ships about 20 lakh orders a year at an average order value of Rs 1,450, roughly Rs 290 crore of gross shipped value. About 70 percent of orders come from tier-2 and tier-3 pincodes, 62 percent of orders are cash on delivery, and everything ships from one warehouse in Bhiwandi. Gross margin on the tag price is a healthy 62 percent and the CEO cannot understand why EBITDA is negative. The board wants to know whether the fix is to raise prices, cut marketing, or something else entirely.
RTO rate, COD vs prepaid
27% vs 4%
Fully loaded cost per RTO
~Rs 450 (approx.)
Annual RTO bleed
~Rs 16 cr, ~7.6% of net revenue (illustrative)
Net delivered revenue
~Rs 209 cr (illustrative)
Target COD RTO after 90-day quick wins
27% to 18%
Draw the chain in both directions, because the reverse chain is where the money is
Forward: Surat fabric mills, job-work stitching units in Jaipur and Ahmedabad, inward QC at Bhiwandi, 3PL first mile, origin sort hub, line haul, destination hub, last-mile rider, customer. Reverse: a failed delivery or a customer return goes back to the destination hub, onto a return-to-origin lane, into Bhiwandi inward, through QC and re-grading, and then either back into sellable stock or into write-off. That reverse path has five nodes, takes 13 to 18 days, and typically has nobody on the org chart carrying a KPI for it, which is the SCOR Return process being run by accident. Say out loud that you will quantify both directions, because a candidate who only draws the forward arrow will diagnose this case as a marketing problem.
Attach cost and days to each node, then demand the RTO reason-code split
Forward freight is about Rs 65 a shipment and 4.5 days to a tier-2 or tier-3 pincode against 2.2 days to a metro; reverse freight is about Rs 60 and 13 to 18 days. RTO (return to origin, the parcel that never reached the customer) runs at 27 percent on COD orders and 4 percent on prepaid, and a further 12 percent of delivered orders come back as post-delivery returns. The single highest-value data request in this case is the RTO reason-code split, which comes back roughly as: customer unreachable or refused at the door 44 percent, incomplete or misrouted address 23 percent, courier attempt failed or falsely marked 19 percent, product or expectation mismatch 14 percent (illustrative). Three of those four are information failures at the point of order capture, not physical logistics failures, and that reframes the entire case.
Benchmark node by node and name the broken one
Make is fine: job-work first-pass yield is 96 percent and OTIF into Bhiwandi is 94 percent, both roughly at industry norm. Forward Deliver is acceptable: the 3PL hits its promised SLA on 92 percent of shipments. Prepaid RTO at 4 percent is normal for Indian fashion; COD RTO at 27 percent is at the ugly end of the typical 20 to 25 percent band for the category. So the broken nodes are the order-capture node, where an unverified phone number and a free-to-refuse payment method create a fake order, and the last-mile node, where courier performance varies enormously by pincode. Commit to that: the constraint is order quality, not warehouse throughput.
Size the prize with the fully loaded cost of an RTO, not the return freight
Of 20 lakh shipments, COD is 12.4 lakh with 27 percent RTO (3.35 lakh) and prepaid is 7.6 lakh with 4 percent RTO (0.3 lakh), so about 3.65 lakh RTOs, 18 percent of everything shipped. Per RTO: forward freight Rs 65, reverse freight Rs 60, packaging Rs 25, warehouse re-grading and QC Rs 15, so Rs 165 of hard logistics cost; add roughly 7 percent of returned units coming back soiled or damaged and written off at a Rs 640 cost, another Rs 45 on average; then add the Rs 240 of performance-marketing spend that acquired an order which never converted to a sale. That is about Rs 450 fully loaded per RTO, so 3.65 lakh times Rs 450 is roughly Rs 16 crore a year. Against net delivered revenue of about Rs 209 crore that is 7.6 percent of the top line, which on its own is larger than the EBITDA hole.
Check whether the demand signal and the network are also feeding the problem
Two secondary findings. First, buying is done as one seasonal drop with an 11-week reorder lead time from job-work units, so hits cannot be repeated and misses cannot be cancelled; 2,400 SKUs are live but 300 SKUs drive 60 percent of volume while the tail sits at 140 days of stock and is eventually dumped through discounting. Second, the single Bhiwandi node means a 4.5-day promise into tier-2 and tier-3 where competitors promise two, and a longer promise mechanically raises refusal and cancellation, which loops straight back into the RTO number. So the network is not the primary cause but it is an amplifier, and the SKU tail is a separate cash problem worth its own line.
Generate levers and kill the obvious one on the trade-off
The instinctive lever is a prepaid discount. Test it: moving COD share from 62 to 45 percent shifts about 3.4 lakh orders to prepaid, each avoiding 0.23 of an RTO, so about 78,000 fewer RTOs times Rs 450 is roughly Rs 3.5 crore saved, but a Rs 75 discount on 3.4 lakh orders costs Rs 2.55 crore, so the lever nearly breaks even. The boring levers win instead: a Rs 49 COD convenience fee is revenue-positive and shifts the same behaviour, mandatory phone-OTP and address validation at checkout kills much of the 23 percent address bucket, a WhatsApp confirm-before-dispatch on COD orders above Rs 2,000 costs well under Rs 1 crore across the base and attacks the 44 percent unreachable bucket, and courier allocation by pincode-level RTO scorecard rather than by rate card fixes the 19 percent failed-attempt bucket. Also make the worst 400 pincodes prepaid-only. Forward-deploying inventory into Delhi NCR and Bengaluru hubs for the top 300 SKUs would cut the promise to 2.5 days, but splitting stock across three locations raises safety stock by roughly 1.7 times by the square-root law and adds about Rs 1.2 crore of fixed cost, so it is justified only on the fast-moving 300, never on the tail.
Recommend with sequencing, a number and a risk
First 90 days, zero capex: COD fee, OTP and address validation, WhatsApp dispatch confirmation, pincode-level courier scorecards and prepaid-only for the worst pincodes. Target RTO from 27 to 18 percent on COD, which is roughly 1.1 lakh fewer RTOs and about Rs 5 crore, plus the COD fee revenue and lower write-offs, so call it Rs 8 to 9 crore of annualised benefit against under Rs 1 crore of cost. Next 6 to 12 months, structural: two forward hubs for the top 300 SKUs, and a second job-work partner on a four-week replenishment cycle so the fast movers can be chased and the tail can be cut from 2,400 to about 1,400 SKUs. Biggest risk: the COD fee suppresses conversion in exactly the tier-2 and tier-3 geographies driving growth, so A/B test it by pincode cluster and judge it on contribution per session rather than on conversion rate, and the one datapoint to pull before committing is delivered-order economics by pincode cluster rather than by channel.
Takeaway: The case looked like a pricing or marketing problem and was actually a Return-node problem that nobody owned. Costing an RTO properly, as freight plus reverse freight plus packaging plus re-grading plus write-off plus the wasted customer-acquisition spend, moves it from Rs 60 to about Rs 450 and makes it the single largest cost line in the business. Once loaded that way the winning levers sit at the order-capture node and cost almost nothing, while the intuitive prepaid discount barely pays for itself, which is exactly why the framework insists you price the trade-off on every lever before recommending one.
Common pitfalls
- •Answering a stockout with 'hold more inventory'. That is treating the symptom. Inventory is the buffer a chain needs because of its lead time and variability, so the real questions are why the lead time is long and why demand is hard to predict.
- •Optimising one node in isolation. The supplier quoting the lowest unit price but sitting 45 days away can raise total landed cost once you count safety stock, expediting and obsolescence. Always argue on total cost to serve, not on the price of a single line item.
- •Treating service level as fixed. A 98 percent fill rate is a choice a company pays for, and it need not be the same for every SKU or channel. Candidates who never question the service level miss one of the biggest and cheapest levers in the case.
- •Skipping the demand signal and going straight to warehouses and trucks. If the forecast is wrong or orders are batched, the bullwhip effect will keep regenerating the problem no matter how good the physical network gets.
- •Listing SCOR or SIMDC buckets without numbers. Saying 'let us look at sourcing, manufacturing, distribution' is a table of contents, not an analysis. Attach a cost and a lead time to each node or you have not started.
- •Ignoring India-specific realities: GST removed the tax reason for state-wise depots but many firms still run legacy networks; road is roughly two-thirds of Indian freight and slower than rail on long hauls; and a large unorganised distributor base means data visibility often stops at the CFA depot.
Interview tips
- •Start by drawing the chain out loud and asking the interviewer to confirm the nodes. It buys you thirty seconds, gets free information, and makes your structure specific to this business instead of generic.
- •Ask for the same two numbers at every node — cost per unit and days — and build up landed cost and total lead time. This one habit turns a vague operations discussion into a quantified diagnosis.
- •Use the vocabulary precisely: fill rate, on-time-in-full, days of inventory, cost to serve, lead time, safety stock, minimum order quantity, changeover time, capacity utilisation, first-pass yield. Interviewers in operations practices listen for it.
- •Know two relationships directionally, not as formulas to recite. Safety stock scales with the square root of lead time, so halving lead time cuts the buffer by about 30 percent. And economic order quantity balances ordering cost against holding cost, so faster or cheaper changeovers justify smaller batches.
- •Say the trade-off before you are asked. Every supply chain move buys one of cost, service or cash by spending another. Naming the price of your own recommendation reads as senior; having the interviewer name it reads as junior.
- •Close on the constraint. State which single node governs the chain, what fixing it is worth in rupees, what you would do in the first 90 days versus what needs capex, and the one data point you would want before committing.
Test yourself
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