Prerequisite Tree - How to construct PRT\'s PDF

Preview

Summary

How to construct PRT's...

Description

Prerequisite Tree Using the TOC prerequisite tree (PRT) Two types of logic used in TOC  Necessary condition o "In order to achieve…, we must have…" Check validity by asking "Have we stated the minimum requirements?"  Sufficient cause (cause-effect) o "If…, and if…, then…" Check by asking "Is this enough (or sufficient) to cause the effect?" Goal Tree, EC, and PRT All use the same type of logic  Goal Tree o Big picture o Strategic level  EC o Resolve inherent conflicts  Eg between 2 CSF's or NC's from GT or two needs in day to day conflicts  Generates creative ideas towards a solution  PRT o Action plan o More tactical Implementing Change The PRT method: 4 steps: 1. State target clearly 2. List obstacles 3. Identify intermediate objectives a. Actions b. Options c. Stepping stones 2. Sequence IO's into a tree The prerequisite tree method 1. State the target clearly  Something that looks hard to achieve  A condition  Often an injection restated as if implemented 2. List all objectives stated as conditions 3. List intermediate objectives (IO's) stated as actions 4. Place all intermediate objectives in time/precedence order starting from the bottom, using "we must do… in order to get over…., before we can do…" and so on, up to "so we can achieve the target. Example:

No standard structure for PRT, but there are recommended practices;  Use hexagonal shapes for obstacles  Use square cornered rectangles for IO's (like injections)  Arrows between IOs show precedence  An arrow goes from the obstacle to the arrow(s) above the corresponding IO

 

Number the obstacles as you list them Number the IOs with corresponding no's

  

One IO can address more than one obstacle An obstacle may need more than one IO Don’t add more than you need

Guidelines for constructing the tree  Start by putting the target at the top, then connect the IOs needed to achieve the target in precedence order below that.  Look for pairs of IO's where one IO has to go before the other  The tree doesn’t have to be linear; it doesn’t have to be any particular shape, it can have many branches, as long as they all come together at the top to achieve the target.  You don’t want to have them all in one single branch  If the steps are not dependent on each other, don’t put them in sequence.  Make sure all the IO's are connected (directly or indirectly) to the target at the top. (They don't need to be connected to one IO at the bottom though) Things to note  Obstacles are things that currently stand in the way of implementing the injection  They currently exist, they are not imagines or potential blocks  They are not effects that may/will occur if the injection is implemented.  Obstacles should be stated as conditions  IO's should be stated as actions, except for the target which is a condition Using PRT's Using a pre requisite tree to help you achieve a target, either a personal target or a team project The method works well for teams Once you've constructed your PRT, start with an IO at the bottom, and achieve that before moving up the tree....