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What Is Software Quality Assurance (SQA)? SQA Benefit and SQA Plan.

By Dinesh Thakur

SQA is a concept that spans across the entire software development process. It focuses on improving the process of development of software so that problems can be prevented before they become a major issue. SQA also involves continuous monitoring of the process and making sure those agreed-upon standards and procedures are followed all along in the development process. It is the process of providing adequate assurance (to clients, senior management and other stakeholders) on (quality of) the process followed in the development of software (so that all concerned are satisfied about the fact that the plans laid out for development have been adhered to and that the software as developed conforms to specifications).

Since SQA can also be considered a’ a process for monitoring oversight in the development process, its activities have to be unbiased and the SQA team needs to given freedom and authority. SQA may be internal or external as per agreed terms. Quality assurance usually also uses date from other supporting processes, like verification & validation, joint reviews, and audits.

The SQA process usually consists of the following tasks:

  1. Process implementation: In this task, the design team in consultation with the development team and the SQA team prepares a (quality assurance) process for the development of the software (project). This process is then synchronized with the related verification and validation, joint review, and audit processes that run concurrently. A plan is then prepared for the quality assurance process activities/tasks, which is documented and stored (for the life of the contract of the project).
  2. Product assurance: In this task, all plans and tasks are documented including their execution so that one can assure that all contractual obligations have been fulfilled.
  3. Process assurance: In this task, assurance is provided that the software (project) process complies with all the provisions of the contract and the plans for the process of development.
  4. Assurance of quality systems: In this task, the SQA team monitors the development process and measures parameters of the software (project), based on which a decision on the assurance of the software is provided.

SQA Benefits

SQA has a host of benefits. It ensures that that software built as per SQA procedures are of specified quality. SOA helps to

  1. Eliminate errors when they are still inexpensive to correct
  2. Improves the quality of the software
  3. Improving the process of creating software
  4. Create a mature software process

The SQA plan

The SQA plan is a document that specifies the process to be followed in each step of the software development and the procedures to be followed in each activity of such a process. The objective of SQA plan is to ensure that the development of the software is based on a course of action and that from time to time the development can be measured controlled and monitored with respect to such a course of action-so that the end product is as per the specifications. The plan is governed by several quality standards, policies and models such as IS09000, SEI CMM and Baldrige.




different strategies for the requirement determination

By Dinesh Thakur

In order to collect information so as to study existing system and to determine information requirement, there are different strategies, which could be used for a purpose. These strategies are discussed below.

Interview

The interview is a face-to face method used for collecting the required data. In this method, a person (the interviewer) asks questions from the other person being interviewed may be formal or informal and the questions asked may be structured or unstructured. The interviewer must plan the interview and should have clear understanding of issues.
Questionnaire

A questionnaire is a term used for almost used for almost any tool that has questions to which individuals respond. The use of questionnaires allows analysts to collect information about various aspects of a system from a large number of persons. The questionnaire may contain structured or unstructured questions. The use of a standardized questionnaire gives more reliable data than other fact finding techniques.
Record Review

Record review is also known as review of documentation. Its main purpose is to establish quantitative information regarding volumes, frequencies, trends, ratios, etc. In record review, analysts examine information that has been recorded about the system and its users. Procedures, manuals and forms are useful sources for the analyst to study the existing systems. The main limitation of this approach is that the documentation on the existing system may not be complete and up-to-date.
Observation

Another information-gathering tool used in system studies is observation. It is the process of recognizing and noticing people, objects and occurrences to obtain information. Observation allows analysts to get information, which is difficult to obtain by any other fact-finding method. This approach is most useful when analysts need to observe the way documents are handled, processes are carried out and whether the specified steps are actually followed. This technique is time consuming and costly. Electronic observation and monitoring methods are being used these days because of their speed and efficiency.




decision analysis with examples

By Dinesh Thakur

In decision-making under risk, the probabilities of various states of nature are assumed to be known. Probabilities of the various states of nature are not known to the decision–maker and thus, he cannot apply the maximization/minimization of expected value criteria as in the case of decision under risk.

In such a decision problem, the following decision rules/criteria, depending upon the attitude of the decision maker, may be applied.

i)   Maximax rule or criterion of optimism.

ii)  Maximin rule or criterion of pessimism.

iii) Criterion of minimize regret, and

iv) Criterion of rationality

i)        Maximax or Criterion of Optimism

In this case, the decision-maker is of optimistic attitude and thus would select the strategy, which will provide him the greatest (max) pay-off under the most favorable or the best condition (max). In the above example, the decision-maker will select strategy S2 which will give him a maximum pay-off Rs.10 lakh for launching a new PC and for the same condition.

 

Strategies

States of nature

 

Same condition

New Competitor

Govt. Ban

(S1)  Modify

7

5

-5

(S2) New product

10

3

-13

(S3)   Do nothing

5

1

-2

 

Strategy               Maximum or the best pay-off

S1                                   7
S2                                   10 ß maximum pay-off
S3                                   5

ii) Maximin or Criterion of Pessimism

As the name of the criterion indicates, the decision maker is of pessimistic attitude and thus will select the strategy which will give him the highest pay-off (max) if the worst condition (min) occurs. Here, the decision–maker, being of pessimistic view, will not like to take any risk and thus will think about the safest position in the worst situation, Thus, the decision-maker will select strategy S3 since in the worst situation (government ban) he will sustain the minimum loss (Rs. 2 lakh) due to this decision.

Strategy                worst or the minimum pay-off

S1                                       -5
S2                                      -13
S3                                      -2ß minimum pay-off




Application of Decision Analysis

By Dinesh Thakur

The decision theory (decision analysis) refers to the techniques for analysis decisions under risk and uncertainty. In the process of decision-making the decision –maker wants to achieve something, which may be called his goal, purpose or objective. The decision –maker may choose one particular alternative, which is called strategy of the decision maker,from among various alternatives.

All alternative and outcomes are assumed to be known. There are certain factors, which affect the outcome for different strategies. But these factors or conditions, also called ‘states of nature, are beyond the control of the decision-maker. The strategy (alternative) along with the state of nature determines the degree to which the goal is actually achieved. A measure of achievement of the goal is called the ‘Pay-off’

The pay-off matrix is used as method of presenting data in decision – analysis. Each cell, which is an intersection of a strategy and a state of nature, contains the pay-off.

 

Strategies

States of nature

 

N1

N2

N3

N4

S1

 

 

 

 

S2

 

 

 

 

S3

 

 

 

 

 

If the state of nature is known with certainty, the decision –maker is required only to select the strategy that provides him the highest pay-off.

Let us explain the concept of the pay-off matrix by taking an example.

Assume that a marketing manager of a computer manufacturer is to choose from three alternatives.

1)      Modify the existing PC to improve its design and processing power.

2)      Launch a new PC having latest technology.

3)      Do nothing, i.e. leave the PC as it is.

There are three states of nature that affect the pay-off from each of the alternative strategies.

These states of nature are:

i)  A competitor may launch a new PC with latest technology.

ii) The government may impose high-excise duty on the manufacture of PCs and reduce excise to minimum on laptops to encourage the use of laptops.

iii) Condition will remain the same as they are.

The various pay-offs (profit or loss) from the combination of a strategy and a state of nature are given in the pay-off matrix in fig. 

           

Strategies

States of nature

 

Same condition

New Competitor 0.40

Govt. Ban 0.20

S1 Modify

7

5

-5

S2New product

10

3

-13

S3Do nothing

5

1

-2

It can be seen that there are three states of nature whose probabilities of occurrence is know. This problem situation is called decision under risk. The probabilities represent the likelihood of occurrence of the specific states of nature, either based on historical data or on personal judgment of the decision-maker. In the above example, the expected value (EV) of each strategy is:

EV of S1= (7)  (0.40)+(5)(0.40)+(-5)(0.20)

            =2.8+2.0-1.0=3.8

EV of S2= (10)(0.40)+(3)(0.40)+(-13)(0.20)

=4.0+1.2-2.6=2.6

EV of S3= (5)(0.40)+(1)(0.40)+(-2)(0.20)

=2.0+0.4-0.4=2.0

The maximum expected value 3.8 lakhs is found to be of the option to modify and if the decision is made based on the expected value objective function, the strategy S1 i.e. to modify the existing PC will be selected.