Competitive analysis establishes who else the business is being compared against, and how.
What is available without spending anything
Their pricing, where published. Their reviews, which state plainly what their customers complain about and value. What they advertise on. How quickly they answer the phone.
Reading competitors' negative reviews is the single most useful and least performed exercise here — it is a list of unmet needs in the market, written by the customers themselves.
The frame
Strengths and weaknesses are internal — what this business does well and badly.
Opportunities and threats are external — what the market is doing regardless of this business.
The value is in being specific. "Good service" is not a strength unless it is demonstrably better and can be shown.
Barriers to entry
What makes it hard for a new competitor to take the work. For most trades these are low: a van, a licence and a phone.
Where barriers are low, the durable advantages are the slow ones — reputation, reviews, relationships, recurring agreements — because they cannot be bought quickly by someone arriving with cheaper prices.
The comparison that misleads
Comparing against the cheapest competitor. There is always one, and they are frequently not covering their costs — see pricing adequacy.
The useful comparison is against businesses winning the work this one wants.
What to do with it
It should change something: price, positioning, response time, or what is emphasised. An analysis that changes nothing was an exercise — see competitive positioning.
Frequency
Annually is enough for most trades. Pricing moves faster and is worth checking more often, particularly where material costs have risen.