By nature of being a startup CEO, I am usually a bit short-staffed, under pressure to make every second count, and performing many different roles during the day.

I love productivity systems and apps and lately I've developed my own, which requires only a regular spreadsheet--Excel or Google docs will do--and it's easier and more effective than any I've tried. It has had a measurable impact on my business and I hope it helps others with high-wire-act projects and what are likely insane schedules.

There are four distinct and simple components, and each one is a powerful piece of the puzzle.

1. Find a partner to hold you accountable.

Develop this with another person who can hold you accountable for repeating this task on a regular basis and act as a sounding board and foil to critique your vision to make it as focused as possible.

I've had a standing meeting once a month with another CEO and this has worked wonders in terms of really identifying things that move the business ahead and get big, strategic things done, despite whatever crises and distractions that come along.

2. Every month, write out a big-picture strategy across functional areas of your business.

This is the most important step and takes effort, collaboration, deep thinking, and analysis. Which is why, as a time-strapped CEO, you can easily let it slip a few weeks or more, or become less formal. But performing this every month, rigorously, is essential.

The strategic plan deserves its own sheet on your spreadsheet. Label it "Month Plan" and make a column for each area of your business that you are focused on, like Sales, Product Development, Financial, Operations, and Marketing. Fill in boxes below that contain high-level strategic items specific to each category. Color-code them to tie them to company objectives, such as "higher customer satisfaction" or "more sales in pipeline." These can go across categories. As this spreadsheet gets updated during the month, it should remain high level, focused solely on strategic items that are critical to company success over the long term.

3. Every day, revisit the strategic view to build a priority list.

Make a second spreadsheet for daily to-dos (I call mine "Today"). Every day (and I mean every day), spend at least five minutes looking at the Month Plan. Then, build a list of things you have to do that day on the daily list. This gets filled up with low-level items like "meet with so-and-so" and "call so-and-so back," but simultaneously features big strategic items you need to get done for the month.

To the right column, assign a time estimate to each item in minutes. Then number them to the left in the order that you are going to do them. At the bottom of the sheet, total the time, and divide by 60, giving you the hours. By doing this, you'll know exactly how much work you can get done for the day, and thus give priority to the right items. When you complete items, delete the time and priority number. The time will re-total to your remaining hours of work.

4. Every time an emergency happens, revisit your priority list.

This is where the magic happens. So now you have this spreadsheet for today, and it's got all the items and you assigned them in order. What happens when the emergency happens and you have a customer you must immediately attend to, or a development issue that requires immediate attention, or an important meeting that was supposed to last one hour went on for three hours? No problem! You have the total hours left at the bottom, which tells you how much time you have left. If it's 3 p.m. and you have until 8 p.m. and you just got off an emergency call, there is no way that you have time for everything you scoped. Just delete the times from lowest-priority items and renumber the rest. So, no matter what the interruption or crisis, you're back on track with the important things and are not working on things that are not.

Follow this simple system and you will be calmer, guided by the big picture while prioritizing the most important work, and dealing with crisis on the fly without derailing strategic goals and priorities.

Nicole Hamilton is the CEO of Tactile Finance, a company building software solutions to accelerate the sale of complex financial products, starting with mortgages, while reducing risk to both banks and consumers. Nicole's career has been in technology management in various industries including medical devices, telecommunication software, consumer products, and data analytics software. Follow her on Twitter @nikhamilton.