Sometimes you need to start your problem solving analysis from the end
Usually we take the first decision on the first event we see, then take the next and so on. But, working backwards technique often solves a problem quickly.
When we face a problem that involves a sequence of events, immediately we start the process with our first decision regarding the first event we see in front of us, then take the second decision and the next and thus move towards the solution event after event. If we are fortunate, we reach the solution somehow. This is START to END step by step problem solving in forward direction. This also is the naturally adopted direction of problem solving for most of us.
Many a time though we need to start our analysis from the end event and work backwards to the beginning event.
Case example 1: Journey planning
When my niece told me her important admission test will be held at Kalyani in the morning I sensed a problem. Kalyani is a few hours' drive away from Kolkata by road. Morning time meant we have to start early and be careful in deciding how we travel. A wrong decision might lead us to failure in reaching at right time.
By the first hand information it seemed it is faster to reach by train rather than by road. But there may be a number of trains in the morning for Kalyani. Now the decision to be taken is - which train to catch?
I asked my niece, "What is the time of reporting?" She said, not very enthusiastically, "It is 8.45 in the morning. It'd take at least an hour to reach Kalyani station from Bidhannagar (our station). There are buses and other conveyances from the station to the venue of test. It'd take at least 15 minutes more to reach the campus." I told her to decide which train to take and its time of arrival at our station.
Next day when I asked her about the situation, she said a little hesitantly, "I think we should take the 6.15 train." When I asked her how she arrived at the decision, she explained, "I got the times of the morning trains. The journey would take about an hour and fifteen minutes. So we would reach Kalyani at about 7.45 safely if we take the 6.15 train." "Alternatives?", I pursued. "There are a few other trains around that time, but this looked to me the most suitable." She replied. Then I explained the goodness of Working backwards approach for this decision making problem. This is a simple problem, but when we face this kind of problem, we always work backward to be absolutely clear about our first decision.
End state: To report at the venue by 8.45 am. So we must target to reach the venue by 8.30 am latest. 15 minutes is the buffer time. In our daily life to be sure of reaching a place or meeting a deadline we always use this buffer time concept. This caters for unforeseen situations.
End minus 1 step: To reach the gate of the venue by 8.20 am, as at least 10 minutes may be required to reach the test hall from the gate of the large campus. This is a small detail and never to be ignored.
End minus 2 step: We should keep at least 30 minutes to reach the test campus gate from Kalyani station. Kalyani is not a large city and transport options may not be many. You need also to account for the time to get down from the train and select and board the conveyance that would take you to the campus gate. Rolling back 30 minutes from 8.20 am, we should then take such a train that would certainly reach Kalyani by 7.50 am.
End minus 3 step: With this theoretically safe time of reaching Kalyani station, we must add some buffer as the train might delay on the way. It might also arrive at Bidhannagar, our starting station later than scheduled time. These delays happen. So, I concluded, It is safer to choose an earlier train. The choice of 6.15 train seemed to be ok, but we chose the 6.10 train to keep the buffer for canceled or delayed trains.
Not very surprisingly our train arrived a bit late. Getting a conveyance from Kalyani station to the test venue campus was a hassle and we had to take a quick last minute decision. We reached finally by 8.35 - safe and dry.
End minus 4 step: With (End minus 3 step) decision taken, journey planning was not over though. I asked her, "To catch the train arriving at 6.10 am, when should we start from home?" That was not complicated, but still it is better to fix this predictable and more certain event also on the event timeline to make the whole timeline transparent involving least amount of decision making and anxiety during the actual journey.
Practical experience says,
There are always deviations from what you plan and what actually happen.
Though the instinctive decision of my niece was not much off the mark, when we finished the systematic journey planning process using working backwards approach, our decision became more robust and we became aware of all the events in the whole journey that we would have to go through. This awareness of details is useful for tackling unforeseen situations with more confidence. All in all, the whole process increased our confidence in our decisions and resulted in reduced anxiety.
For my niece it was her first journey outside Kolkata where she had to take part in decision making. When I discussed this problem with one of my younger but more experienced friends, his time estimates were spot on and coincided with our estimates. Invariably he started from End event - the goal. My friend remarked casually, "When we started our career we also tried to plan our journey from the starting time, not the ending target time. Now with experience we do backwards journey planning using buffer times automatically."
Experience builds similar kinds of problem solving mechanisms in most people but with varying degrees of intensity.
Case example 2: Thinking backwards to locate misplaced or lost items
In Personal life, I resort often to working backwards to remember where and when I misplaced or lost an important item. Especially I remember a day when I was moving through a series of hectic actions, often going out of my home. Whenever I go out I lock the gate and take the key with me. Other members can open the gate in my absence with duplicate keys and when I return I won't have to bother anyone for opening the door. That particular day when I returned home finally, I found the door open. After entering I reached for my key in my pocket to place it on the key hook by the side of the door, I found I don't have the key. I was deeply shocked.
Losing the bunch of keys outside my home would have serious consequences. I have to change all the keys in the bunch for safety—a very tedious and irritating process.
With a duplicate bunch of keys I went out again and slowly retraced my path to a nearby workshop. All the while my eyes were searching on the road surface for a gleam of metal. No trace at all. Even when I reached the last visited workshop, I found it closed and no bunch of keys lying nearby.
Dejected I returned. This time after settling down I started thinking. Which of the rooms I went to before I left for the first time? Moving through my rooms with half expectation I was more relieved than surprised to find the key bunch lying innocently on a corner of my table. While in hurry, I took the bunch but didn't take it with me when I went out. Instead, in between my hectic activities, I put it on the table and forgot all about it.
Working backwards approach is a powerful problem solving technique used in many real life problem solving situations. For planning and execution of large and complex projects with fixed target time point, working backwards is an essentiality.
Though we use this technique frequently in real life, we find from the literature available that formalism to this approach was given by the mathematicians. This is not very surprising, as effects of problem solving techniques or approaches can be very clearly demonstrated in the more certain and specific world of mathematics.
Can you identify other real life scenarios where working backwards produces much better results?
Preparing for an exam, preparing for a lecture, organizing for an event where you have fixed amount of preparation time are only some of the real life scenarios where you would automatically use this powerful problem solving approach.
Frequent use of such a basic problem solving technique makes it a part of your reflexive problem solving mechanism, no less.
Example: Working Backwards Technique for Inventive Problem Solving
How Could Sonia Sell Half a Poodle Riddle
Many Applications of Working Backwards Technique
The list is long and can be extended further. It gives an idea how basic this unusual thinking process is. Ponder a moment on each to imagine how the technique may wotk in the area.
- Working backwards in mathematics
- Working backwards in puzzle solving
- Working backwards in journey planning
- Working backwards in conflict management
- Working backwards for event management
- Working backwards for scheduling exam preparation
- Working backwards to catch a murder in detective work
- Working backwards in psychiatric treatment of a trauma patient
- Working backwards in reverse engineering
- Working backwards in project management
- Working backwards for product launch
- Working Backwards in Financial Planning
- Working Backwards in Software Development
- Working Backwards in Supply Chain Management
- Working Backwards in Crisis Management
- Working Backwards in Career Planning
- Working Backwards in Marketing Campaigns
- Working Backwards in Urban Planning
- Working Backwards in Environmental Policy Development
- Working Backwards in Historical Research
- Working Backwards in Recipe Development
- Working Backwards in Real Estate Development
- Working Backwards in Business Strategy
- Working Backwards in Artistic Creation
- Working Backwards in Legislative Processes
- Working Backwards in Educational Curriculum Design
- Working Backwards in Diplomatic Negotiations
- Working Backwards in Theater Production
- Working Backwards in Sports Coaching
- Working Backwards in Customer Service
- Working Backwards in Novel Writing