With all of the buzz surrounding company culture right now, it often seems like it’s hailed as the miracle cure for everything. Simply craft a few values, and your business is instantly transformed for the better. Is it really that easy?

Like most company leaders, you’re probably aware that culture matters, and that it can have a strong impact on performance. Studies now confirm that it is considered as important to success as strategy, and in fact it should be a strategy in itself. Yet, so many culture change efforts either fail completely, or fall far short of their potential.

So why is this? Is company culture not all it’s cracked up to be?

From the many cultural programs Beliyf has worked on, we’ve got to experience firsthand why some succeed, and others fail. Often, leaders who are looking for an instant antidote to their plummeting sales figures, or a quick employee ‘morale boost’ are the ones who are most disappointed. You see, changing or transforming an organisational culture, is not an initiative to be undertaken lightly: culture is a treaty, not a tactic.

Frustrated by the countless articles that cite culture as some kind of ‘silver bullet’, we felt it was time to share the real story of what is involved; to reframe the conversation in a realistic manner, so that only those who are up for the task, actually embark on it. Maybe this way, we can begin to improve the ratio of the number of successful culture initiatives.

If you’re a leader who is looking to define, improve or overhaul your company’s culture, here are the five things you must be aware of before writing your first core value.

1. It will slow you down when recruiting

For more than two decades, Southwest Airlines has been ranked as one of the best places to work by Forbes, Fortune, Glassdoor, and others. But it’s not an easy place to get into. In 2015, the company received 371,202 CV’s and hired nearly 6,000 new employees — less than 2 percent of all applicants. According to Shari Conaway, Director of People Development at the carrier, “It is not unusual for us to interview more than 100 people to fill a single position…We intentionally spend an inordinate amount of time on the recruiting and hiring process.” In order to preserve its unique personality and culture, Southwest understands the importance of hiring for ‘fit’ as well as ‘competence’.

Online shoe and clothing store Zappos shares a similar outlook: “We infuse culture into every step of the recruiting process,” says Mike Bailen, Senior HR Manager at the company. “We really place such a high value on culture that if a candidate demonstrates behaviours out of alignment with our core values, we will stop the process right there.”

Hiring for cultural fit doesn’t make for a quick and easy recruitment operation. You might even find yourself turning down people who you feel might be able to hit the ground running very quickly. But technical ability isn’t the be all and end all – and remember; technical skills can be taught; motivation and passion cannot.

2. It means making tough decisions

Speaking in HR Magazine, The National Gallery HR Director, RoseMarie Loft describes how she does not want “a batch of clones to give me an easy life”. She speaks of the “shared values” that have to be present – “simply because if an employee is completely opposed to what you are doing, neither of you is going to be happy”.

Take the example of a top performing salesman – who when he’s in the office, takes every opportunity to belittle junior staff. Or a technically gifted developer, who regards collaboration as a distraction. An easy life means keeping things (and people) untouched. But if you actually want to remove damaging or toxic elements of your current culture, it sometimes calls for difficult and unpopular decisions.

As Buffer, the social account management company started to grow, the time came to put its culture into words; to work out what it takes to build and maintain a cohesive team that works together. As the founder, Joel Gascoigne explained, this meant “finding people who are positive and happy, with a focus on self-improvement, who have gratitude, are humble and are comfortable with your extreme transparency”.

Yes, it meant refiguring the company’s recruitment process. But much tougher than this was the realisation that “some people didn’t fit the culture and letting go was inevitable”.

Dave Kashen refers to the importance not just of “who you let on the bus”, but also “who you make sure gets off the bus”. For Buffer, this meant parting ways with nearly 50% of its entire workforce (six people out of 13). Not easy – but necessary if culture is a top priority.

3. It doesn’t happen overnight

Sir Alex Ferguson spent 26 seasons as the manager of Manchester United football club. Under his stewardship, Man Utd bagged 38 trophies, including 13 Premier League titles, five FA Cups and two UEFA Champions League titles. His accomplishments are nearly double that of the next-most-successful English club manager.

Reflecting on what guided him to achieve such results, Ferguson told HBR “From the moment I got to Manchester United, I thought of only one thing: building a football club. I wanted to build right from the bottom… Winning a game is only a short-term gain – you can lose the next game. Building a club brings stability and consistency.”

Building a high-performance, sustainable culture doesn’t happen overnight. It’s an ongoing commitment, rather than a short-term solution. Modern Survey’s Don MacPherson describes how easy it is for CEOs and HR managers to become crestfallen when faced with the reality, “They want the culture they want now, not in three years…”.

He describes a three-stage process for effective cultural change: senior leaders defining what they want, before imparting those objectives to front line managers, culminating in a process of getting employees on board with the changes made. This latter stage is where “employees either fall in line or leave the organisation”.

So it’s not a case of making a handful of cosmetic changes, standing back and enjoying the fruits of your efforts. It’s an involved process – and for a small to medium-sized company it can take 12-18 months for the benefits of positive change to really start to feed through.

4. It starts with you

An organisational culture isn’t plucked from thin air. It has to be built around something, and that something is you. In fact it’s a foundational, yet overlooked rule of culture, that companies will grow to emulate the behaviours and personalities of their founders.

This is the reason why so many culture initiatives fail. Improving, changing or defining your culture, cannot be relegated as a tactical exercise to your HR or Marketing teams. Writing for HBR, Red Hat CEO Jim Whitehurst states “How we behave as leaders drives the kind of culture we end up with”. He believes that if a leader wants to change the culture of their organisation, their first step should be to “Look in the mirror and make sure you are setting the kind of behavioural example you want everyone else to follow”.

Author Scott Berkun seconds this: “It’s the CEO’s actual behavior, not their speeches or the list of values they have put up on posters, that defines what the culture is”.

“An organisation’s culture is not about words at all. It’s about behaviour — and consequences.” – Jack Welch

Molly Graham, former Culture Manager of Facebook shares a similar opinion “If a founder is competitive, the company will be more aggressive and competitive. If they are analytical and data-driven, the company will tend to make metrics-based decisions… If a founder is a designer, the way the company builds products will likely be led by design.”

As the founder or CEO of your organisation, you are its biggest cultural influence. If you’re not prepared to role-model the behaviours that you want to see in others, don’t embark on a culture change program. Claiming your company has values that you don’t personally emulate won’t drive performance, but it will drive cynicism.

5. It can’t be copied and pasted

There are no ‘top 10 features’ of a great company culture. Google’s culture is feted frequently. But Google’s culture has been conceived, developed and honed for Google: it’s not a template to be lifted and applied universally. The same applies to any existing company culture – so being constantly “hungry, nimble and desperate” in the vein of Amazon probably doesn’t apply to you either. Quite simply, it doesn’t belong to you.

Lifting certain practices or attitudes isn’t going to work if they don’t reflect who you are. Why would you institute a bring your dog to work day if you hate dogs – or a flexible working policy if you’re going to tut when people aren’t sat at their desks?

Authenticity is what makes a great culture. Just because a policy works for one company, doesn’t mean that it’s going to drive performance or engagement for another.

This absence of a template is actually one of the biggest advantages of developing a strong company culture. The end results belong to you and you alone. You might wake up to find that your prices have been undercut, or your product copied, but the essence of your organisation – the spirit that helped make it successful in the first place cannot be lifted.

So why even bother?

If focusing on and developing your company culture isn’t easy, then why do it? The answer, of course, is that nothing that’s truly worthwhile is ever easy.

Time and again, experience shows that investing in culture pays dividends. To take just one example, of 1400 CEOs and CFOs interviewed late last year, almost all recognised that improving corporate culture would improve the value of the company, while more than half said it influences productivity, profitability, firm value and growth rates.

Culture might not be a silver bullet; but it’s the only sustainable, competitive advantage your company has, that leads to fanatically loyal customers, employees and stakeholders.