A company wants to figure out which of its IT systems actually help it win against competitors, versus which ones just keep the lights on. What technique from business strategy does an enterprise architect typically borrow to make that distinction, and how does it work?
answer
- Porter's value chain
- primary vs support activities
- differentiator vs commodity IT spend
- overlay systems onto activities
- Walmart logistics example
basics
~20 sEnterprise architects use Porter's value chain to map out every business activity, from making the product to selling it, and check which IT systems support the activities that make money versus the ones that just keep things running.
solid answer
~30 sThey borrow Michael Porter's value chain, which splits a company's activities into primary activities (inbound logistics, operations, outbound logistics, marketing/sales, service) and support activities (infrastructure, HR, technology development, procurement). An architect overlays IT systems onto each activity and asks which ones create a cost advantage or differentiation the customer will pay for, versus which are pure overhead. Systems tied to primary/differentiating activities get investment priority and closer business partnership; commodity support-activity systems (payroll, generic email) get standardized, outsourced, or minimized. This turns a vague 'align IT with the business' mandate into a concrete map of where technology spend should concentrate.
go deeper
Should recognize the basic split between activities that touch the customer/product (primary) and activities that keep the lights on (support), and give one example of each.
Should be able to actually map 2-3 real systems from a project they've worked on onto value chain activities and argue which ones deserve customization vs off-the-shelf treatment.
Should push back on where the model breaks down (platform businesses, evolving commoditization) and connect the exercise to concrete portfolio decisions like build-vs-buy and funding allocation.
Should treat this as one input among several (with capability heat maps, TBM, portfolio management) and be able to explain how it feeds governance forums and investment committees, plus when to sunset or re-run the exercise.
## What the value chain decomposes Michael Porter introduced the value chain in his 1985 book Competitive Advantage as a way to decompose a company into the discrete activities it performs to design, produce, market, deliver, and support its product or service. The model splits activities into two categories: - **Primary activities** that touch the product directly — inbound logistics, operations, outbound logistics, marketing and sales, and service. - **Support activities** that make the primary ones possible — firm infrastructure, human resource management, technology development, and procurement. Each activity has a cost and, ideally, contributes a **margin**: the difference between what customers will pay and what it costs the company to perform all the linked activities. ## The mechanism — overlay systems onto the activities they support Enterprise architects reuse this decomposition for a specific reason: 'align IT with the business' is meaningless until you can point at which piece of the business a given system actually touches, and whether that piece is where the company competes or just where it has to show up. The mechanism is to take the organization's value chain and overlay every major application, platform, or IT capability onto the activity or activities it supports: - A CRM and a real-time pricing engine map onto marketing/sales. - A warehouse management system maps onto outbound logistics. - A payroll system maps onto HR, a support activity. This overlay produces a view that separates systems into two buckets: - Those supporting activities where the company **differentiates** or competes on cost. - Those supporting activities that are necessary **overhead** shared by every competitor in the industry. ## Why it exists — where technology spend should concentrate The reason this exists is to fix a specific, recurring failure of IT investment: treating every system request with the same governance and the same appetite for customization, so that a commodity payroll system gets bespoke integrations while an actual differentiator — say, a recommendation engine — gets starved because it competes for budget on equal footing with things that create no competitive advantage. Value chain mapping forces a conversation about where technology spend should concentrate: - Activities identified as sources of **competitive advantage** justify custom build, deep IT-business partnership, and faster iteration. - Activities that are **pure support** justify buying an off-the-shelf SaaS product, standardizing, or outsourcing entirely, because differentiating there produces no return. ## The trade-off The trade-off is that this decomposition is a simplification of a much messier reality. 1. **Designed for manufacturing-era, largely linear businesses.** Value chains were designed for manufacturing-era, largely linear businesses; a platform business or a two-sided marketplace does not decompose cleanly into inbound-logistics-to-service sequences, and analysts have proposed alternatives like value networks or value shops for those cases. Applying the classic value chain rigidly to, say, a social media platform can misclassify genuinely strategic capabilities (like the recommendation algorithm or the ad-matching engine) as 'technology development,' a support activity, understating their importance. 2. **A point-in-time snapshot.** The other cost is that the mapping is a point-in-time snapshot; what counts as a differentiating activity shifts as competitors catch up — an online checkout flow was a differentiator for early e-commerce and is now table stakes for everyone, so systems that once justified premium investment should eventually be reclassified as commodity and cost-optimized. ## Failure modes 1. **A one-time diagram rather than a living input.** The most common production-grade failure mode is treating the value chain exercise as a one-time architecture diagram rather than a living input to portfolio decisions. Teams draw the chain, get sign-off, and never revisit it, so two years later the 'differentiating' bucket still contains systems that have become commodities, and genuinely new differentiators (a fraud-detection model, a personalization pipeline) never get mapped in and so never get prioritized funding. 2. **Too coarse a grain.** A second failure is mapping at too coarse a grain — labeling all of 'marketing and sales' as differentiating lets low-value marginal systems ride on the coattails of the genuinely strategic ones, defeating the purpose of doing the exercise at all. ## Where it shows up A concrete, widely cited real-world pattern: retail and logistics companies (Walmart's investment in supply-chain visibility and cross-docking systems is the textbook example) used value-chain thinking to identify inbound/outbound logistics as their competitive battleground and poured disproportionate IT investment there — building proprietary systems years ahead of competitors — while running HR and finance systems on largely standardized, vendor-supplied platforms, because no customer ever chose Walmart for its payroll system.
- How is this value-chain-to-IT overlay different from a business capability heat map?The value chain is a linear, activity-based decomposition borrowed from Porter that emphasizes sequence and margin, useful for spotting where competitive advantage is created. A capability heat map is a non-sequential inventory of 'what the business does' (capabilities), colored by attributes like maturity, cost, or redundancy, and is better suited to spotting duplicate systems or underinvested capabilities across a large, non-linear organization. Many EA practices use both together: value chain for the 'where do we compete' question, heat map for the 'where is our portfolio inefficient' question.
- What would make you NOT use value chain analysis for an alignment exercise?If the business is a platform or marketplace whose value comes from network effects rather than a linear sequence of activities, forcing it into inbound-logistics-to-service boxes obscures more than it reveals; a value network or ecosystem map fits better. It is also a poor fit for a very small organization where the overhead of the exercise exceeds the clarity gained — a 20-person startup does not need a formal value chain workshop to know its product engineering is the differentiator.
Think of the value chain like a factory floor tour: you walk the line and tag each machine as either the one that makes your product better than the competitor's (worth customizing and upgrading) or just the forklift that moves boxes (worth renting the cheapest one available).
saying these in an interview costs you the question
- Treats every IT system as equally strategic, no differentiation
- Confuses this with a technical architecture diagram
- Never revisits the classification as the business changes
- Cannot say which activities are commodity vs competitive advantage
- Applies it uncritically to a non-linear/platform business