Stepwise Refinement

“You take in elephants one spoonful at a time.”
– Bryce’s Law

In a nutshell, the concept of “stepwise refinement” is to take an object and shift it from a basic perspective to a precise stage of detail. Architects have utilized these an approach for yrs, as have engineers constructing products and solutions. But to do so, they realized they are not able to simply just go from the basic to the particular in one felled swoop, but in its place, in increments (techniques). The amount of techniques required to decompose an object into enough detail is in the long run primarily based on the inherent mother nature of the object. To illustrate, for architects building a constructing, the typical techniques include:

  1. Develop artist rendering (to take into account viability).
  2. Style and design basis and superstructure.
  3. Style and design Flooring programs.
  4. Style and design electrical and plumbing diagrams.

In other words and phrases, right before the first shovel of dirt is dug on the venture, the architect knows precisely what the constructing will seem like and how it will get the job done. All of the guess get the job done has been eradicated.

Engineers constructing products and solutions these as automobiles abide by very similar but distinct techniques:

  1. Develop artist rendering (to take into account viability).
  2. Style and design major assemblies (e.g., chassis, human body)
  3. Style and design subassemblies (e.g., engine, transmission, electrical, and so forth.)
  4. Style and design operations (e.g., the several factors of the engine).

Like the architects, the engineers know precisely how the automobile will seem, the components required to deliver it, and the sequencing of assembly. All of the guess get the job done has been eradicated.

“Stepwise refinement” in the long run represents a “divide and conquer” approach to design and style. In other words and phrases, split a complicated object into scaled-down, a lot more workable items that can be reviewed and inspected right before relocating to the following stage of detail.

There are those in the I.T. subject that sense these an approach is impractical to put into action, and in its place of engineering your way to results, you ought to take an original stab at producing a method, then keep on to modify it right up until you have created some thing to pacify the user’s needs. This of program is a hacker’s approach to improvement and may possibly be fine for producing an innocuous minor method but unquestionably not suited for producing just about anything of compound.

Can the concept of “stepwise refinement” be used to a single method? Totally. As a issue of point, it lies at the main of the structured programming motion of the 1970’s-80’s. But can it be used on a grander scale, these as an organization-huge Information Method. Again, the remedy is Yes. In point, it is the sensible way of attacking these a major endeavor.

In advance of we can tackle an information process, it would make feeling that we first understood the inherent homes or construction of the object of our consideration. It has often been our competition that an Information Method is a merchandise that can be engineered and made like any other merchandise. To this close, we see an Information Method as a 4 stage hierarchical construction consisting of the adhering to factors:

Degree one – Method – symbolizing the all round merchandise to be created.

Degree 2 – SUB-Methods – symbolizing the business enterprise procedures linked with the process (one or a lot more).

Degree 3 – Procedures – symbolizing the get the job done flow of each sub-process. There are vital two varieties of methods Administrative – symbolizing methods executed by individuals and Personal computer.

Degree four – Applications – symbolizing the plans required to execute each computer system procedure.

As an apart, there is also a Degree four for Administrative Procedures (to produce the guidelines/techniques pertaining to the procedure), but for the functions of this paper, let us place this apart for the moment.

Beneath “stepwise refinement” the amounts are decomposed prime-down through the design and style approach, and carried out base-up a typical engineering/production procedure.

To put into action this approach, a “blueprinting” procedure is utilized which is essentially not as well dissimilar with that utilized by architects and engineers in other fields. Listed here, the blueprints are utilized to express the succeeding amounts in the process hierarchy. To illustrate, take into account the adhering to diagram, the place the get the job done from the previous stage feeds the following stage in the process hierarchy:

What this signifies is that all of the guess get the job done has been eradicated. So much so, that the creation of executable plans ought to be a somewhat easy job. Again, the requirements for the plans had been created normally in scaled-down and a lot more workable increments, not all in when.


The concept of “stepwise refinement” is not accurately new and has been utilized successfully in the engineering/production of products and solutions for several yrs as a signifies to regulate complexity. It has only been in the final 30 yrs that people have been hoping to put into action the procedure in the improvement of programs and computer software.

In the absence of “stepwise refinement” on a complicated process, the “brute drive” approach is commonly utilized, whereby superficial get the job done is completed in the previously phases and significantly a lot more time is invested in programming next-guessing what is to be created. This is one cause why businesses currently almost never tackle major programs improvement assignments, and are content with attacking it in piecemeal.

But if you can assimilate a process as a merchandise, and feel it can be engineered and made like any other merchandise, than “stepwise refinement” is a pragmatic option you can unquestionably use.

If you would like to discuss this with me in a lot more depth, be sure to do not wait to send me an e-mail.